/"/7CP 


Mam  Li* 


LUTHER  BURBANK 


GATHERING  POPPIES. 

The  selected  varieties  of  red  oriental  poppies  blossom  early  and 
late  at  Sebastopol.  This  piclure  was  taken  in  March,  1914,  not  long 
after  Mr.  Burbank's  sixty-fifth  birthday.  It  is  an  excellent  portrait 
of  the  plant  developer  as  he  is  to-day. 


LUTHER    BURBANK 

HIS    LIFE    AND    WORK 


By 
HENRY  SMITH  WILLIAMS,  M.D.,  LL.D. 

AUTHOR  OF  "MODERN  WARFARE,"  "ADDING  YEARS  TO  YOUR  LIFE"  ; 
EDITOR  IN  CHIEF  OF  THE  LUTHER  BURBANK  SOCIETY 


ILLUSTRATIONS  IN  COLORS  AND  BLACK  AND 
WHITE  FROM  PHOTOGRAPHS 


NEW  YORK 

HEARST'S    INTERNATIONAL    LIBRARY  CO. 
1915 


Copyright,  1915,  by 

HEARST'S  INTERNATIONAL  LIBRARY  Co.,  INC. 

All  rights  reserved,  including  that  of  translation  into  the  foreign 

languages,  including  the  Scandinavian 

^    /  r/7 


•        *   %,«•   . 


5/3*3 


CONTENTS 

CHAPTER  PAGE 

INTRODUCTION    ...       .       .       .     ix 

PAET  I 

LUTHER  BURBANK  THE  MAN,  AND  AN 
OUTLINE  OF  HIS  METHODS 

I     LUTHER  BURBANK:  THE  MAN  AND  His 

WORK     .       .       .       .       .       .       .3 

II    THEORIES  OF  PLANT  DEVELOPMENT  .       .     24 

PART  II 

WITH  LUTHER  BURBANK  IN  ORCHARD, 
GARDEN,  FIELD,  AND  FOREST 

III  THE  CARE  OF  SEEDS  AND  SEEDLINGS    .     45 

IV  WITH  BURBANK  IN  THE  ORCHARD  .       .     56 
V    NEW  BERRIES  AND  GARDEN  FRUITS        .     80 

VI    BURBANK  IN  THE  VEGETABLE  GARDEN    .  107 
VII    BURBANK  IN  THE  FLOWER  GARDEN  .       .  131 
VIII    THEORY  AND  PRACTICE     .       .       ,       .  156 
IX    BURBANK  's    METHOD    OF    BEAUTIFYING 

LAWN  AND  DOORYARD  ....  170 
X    BURBANK  's  WAY  WITH  TREES       .       .  206 
[v] 


393739 


CONTENTS 

PART  HI 

BURBANK'S  METHODS  AND  THE  HUMAN 
PLANT 

CHAPTER  PAGE 

XI    THE  BEEEDING  OF  MEN    ....       .  239 
XII    THE  LAWS  OF  HEEEDITY — THEIR  DEFI- 
NITE MEANING  AND  INTERPRETATION  .  262 
XIII    NURTURE  versus  NATURE  .  .  295 


[vi] 


LIST  OF  ILLUSTRATIONS 

Gathering  Poppies  (color)       .       .       .      Frontispiece 

TAC1NO 
PAGE 

A  Cluster  of  Burbank  Plums 8 

A  Group  of  Stoneless  Plums 16 

A  Fruit-bearing  Slab  of  Spineless  Cactus      .       .  24 
Mr.  Burbank  Inspecting  a  Choice  Variety  of  Spine- 
less Cactus .  32 

A  Field  of  Spineless  Cactus  at  Santa  Kosa    .       .  40 
Spineless  Cactus  in  Fruit  .       .       .       .               .48 
Boxes  of  Seedlings  in  Mr.  Burbank 's  Conservatory  56 
Mr.  Burbank  Inspecting  Cross-bred  Tomato  Seed- 
lings               .  .    .  64 

The  Culture  of  Seedlings  at  Santa  Rosa  .       .       ;•:  72 

A  Cleft  Graft  (color) .80 

Cultivating  the  Fruit  Orchards         ....  88 

The  Process  of  Grafting  Completed  ....  96 

A  Brand-new  Burbank  Fruit — the  Plumcot  (color)  104 

Mr.  Burbank 's  Phenomenal  Berry  ....  112 

Mr.  Burbank 's  White  Blackberry  (color)       .       .  120 

The  Burbank  Thornless  Blackberry  ....  128 

Inspecting  Hybrid  Blackberries       .       .       .       .  136 

Mr.  Burbank 's  Himalaya  Blackberry       .       .       .  144 

Mr.  Burbank  Inspecting  Garlic  Seedlings       .       .  152 
The  Camassia — a  Flowering  Food  Plant       .       .160 

Burbank 's  Onions  Grown  for  Seed  (color)       .       .  168 

Mr.  Burbank  Planting  Choice  Seeds       .       .       .  176 

A  Burbank  Hybrid  Tigridia  (color)        V.      .       .  184 

A  View  of  Mr.  Burbank 's  Garden  at  Sebastopol    .  192 

[vii] 


LIST  OF  ILLUSTRATIONS 


PAGE 


Beds  of  Shasta  Daisies 200 

Quantity  Production  Applied  to  the  Watsonia  .  208 

A  New  Burbank  Eose 216 

An  Interesting  Variety  of  Evening  Primrose  .  .  224 

A  Burbank  Hybrid  Dahlia  (color)  ....  232 

Rows  of  Hybrid  Amaryllis 240 

One  of  Mr.  Burbank 's  New  Varieties  of  Giant 

Amaryllis .  248 

A  Gigantic  Bulb 256 

Quantity  Production  Applied  to  the  Australian 

Star  Flower 264 

A  Miniature  Chestnut  Tree 272 

A  Dwarf  Chestnut  (color) 280 

Grafting  Fruit  Trees  at  Sebastopol  ....  288 

Hybrid  Massachusetts  Elm  on  California  Roots  .  296 

A  Fine  Specimen  of  the  Royal  Walnut  .  .  .  304 

Variation  Among  the  Canes  of  Seedling  Briars  .  312 


[viii] 


INTRODUCTION 

EVERYONE  knows  that  marvelous  work  in 
developing  new  forms  of  plant  life  has  been 
performed  by  Luther  Burbank  at  Santa 
Rosa,  California.  Indeed,  the  name  Burbank  is 
a  household  word.  And  yet  when  you  come  to 
question  people  as  to  their  precise  knowledge  of 
what  Mr.  Burbank  has  done,  you  find  that,  as  a 
rule,  their  information  is  singularly  vague.  They 
may  have  heard  of  the  Burbank  potato,  the  stone- 
less  plum,  the  Shasta  daisy,  the  white  blackberry, 
or  the  spineless  cactus.  But  something  like  this 
is  pretty  sure  to  be  the  full  measure  of  their 
knowledge  as  to  the  Santa  Rosa  experimenter's 
specific  accomplishments. 

This  is  not  strange,  for  until  recently  there  has 
been  no  authoritative  and  comprehensive  account 
of  just  what  Mr.  Burbank  has  really  done,  much 
less  how  he  does  it. 

Now,  to  be  sure,  Mr.  Burbank 's  own  account 
of  his  lifework  is  available  in  twelve  large  vol- 
umes with  more  than  twelve  hundred  illustrations, 
all  in  color.  There  is  no  longer  any  reason  why 
the  critic  should  be  in  doubt  as  to  just  what  Mr. 
Burbank  has  done,  just  what  are  his  theories  and 
methods.  But  of  course  not  everyone  has  yet 
seen  the  comprehensive  work  in  question,  so  it 
still  seems  desirable  to  give  a  briefer  account  of 

[ix] 


INTRODUCTION 

the  methods  and  results  of  the  Santa  Eosa  ex- 
perimenter. This  is  done  in  the  present  volume, 
which,  obviously,  makes  no  pretense  to  compete 
with  the  series  of  volumes  just  referred  to,  as 
issued  by  the  Luther  Burbank  Society ;  but  which 
might  rather  be  considered  as  preliminary  or  sup- 
plementary to  those  volumes. 

Some  readers  of  these  pages,  I  trust,  will  be 
stimulated  to  seek  at  first  hand  the  pages  of  the 
larger  work,  to  read  extensive  accounts  of  things 
that  are  necessarily  treated  here  with  brevity  or 
barely  referred  to. 

And,  on  the  other  hand,  it  is  not  unlikely  that 
some  possessors  of  the  larger  work  may  find  the 
present  volume  a  convenient  summary,  serving 
the  purposes  of  recapitulation. 

It  should  perhaps  be  explained  that  Mr.  Bur- 
bank  is  in  no  wise  responsible  for  the  present 
book,  except  in  the  sense  that  his  work  furnished 
the  foundation  for  it.  Mr.  Burbank  must  not  be 
held  responsible  for  any  theories  or  statements 
herein  made,  unless  particularly  accredited  to 
him.  But,  as  evidencing  the  authenticity  of  the 
main  presentation  of  his  theories  and  the  chief 
summary  of  his  work  here  presented,  it  is  per- 
missible to  recall  that  the  writer  has  acted  as 
editor-in-chief  of  the  series  of  volumes  above  re- 
ferred to,  and  that  in  that  capacity  he  has  had 
access  to  all  Mr.  Burbank 's  original  manuscripts 
and  records,  in  addition  to  spending  several 
weeks  in  close  personal  communion  with  the  plant 
developer  himself  at  Santa  Eosa,  every  aspect  of 


INTRODUCTION 

his  work  being  the  subject  of  detailed  and  elab- 
orate discussion. 

The  illustrations  of  the  series  of  volumes  issued 
by  the  Luther  Burbank  Society — bearing  title 
"Luther  Burbank:  His  Methods  and  Discoveries 
and  Their  Practical  Application " — constitute 
probably  the  most  remarkable  set  of  color  pic- 
tures ever  published  in  connection  with  any 
single  work  dealing  with  plant  life.  They  are 
1260  in  number,  reproduced  in  the  main  from 
direct  color  photographs  made  on  Lumiere  plates ; 
and  they  show  every  aspect  of  Mr.  Burbank 's 
work,  and  typical  specimens  of  his  achievements 
in  plant  development. 

We  are  permitted  to  reproduce  eight  of  these 
pictures  in  the  present  volume,  through  courtesy 
of  the  Luther  Burbank  Society.  A  glance  at  these 
will  give  the  reader  some  intimation  of  the 
sumptuousness  of  the  almost  endlessly  varied 
mass  of  color  illustrations  from  which  these  are 
excerpted. 

The  black-and-white  illustrations  of  the  present 
volume  are  partly  from  other  photographs  be- 
longing to  the  Luther  Burbank  Society,  and  partly 
from  original  photographs  by  the  author,  who  has 
perhaps  put  Mr.  Burbank 's  unfailing  good  humor 
to  severer  test  by  his  persistent  use  of  the  camera 
at  Santa  Rosa  and  Sebastopol  than  it  was  ever 
otherwise  similarly  tested.  For  the  famous  ex- 
perimenter is  a  very  modest  man,  and  the  sight 
of  a  camera  fills  him  with  trepidation.  Fortu- 
nately, however,  he  is  as  accommodating  as  he  is 

[xi] 


INTRODUCTION 

modest,  and  as  the  writer  was  given  permission 
to  make  snapshots  quite  without  restriction,  we 
are  able  to  present  unique  views  of  Mr.  Burbank 
in  action — views  that  will  be  highly  appreciated 
by  plant  lovers  who  have  not  been  privileged  to 
visit  Santa  Rosa  in  person,  and  to  whom  the  per- 
sonality of  the  famous  experimenter  is  the  sub- 
ject of  legitimate  interest. 

It  will  be  seen  that  the  subject-matter  of  the 
present  volume  is  divided  into  three  parts :  the 
first  dealing  with  the  life  and  personality  of  Mr. 
Burbank,  and  with  an  outline  of  his  theories ;  the 
second  with  a  detailed  treatment  of  his  practical 
methods  as  applied  in  orchard  and  garden  and 
field  and  forest ;  and  the  third  with  an  attempt  to 
interpret  his  work  in  its  possible  application  to 
what  he  has  picturesquely  spoken  of  as  the  breed- 
ing of  the  human  plant.  The  last-named  subject 
carries  us  somewhat  afield  from  Mr.  Burbank 's 
direct  activities,  but  it  deals  with  matters  of  obvi- 
ous importance,  and  matters  in  which  Mr.  Bur- 
bank  himself  takes  the  keenest  interest.  It  should 
be  added  that  the  chief  part  of  the  matter  in- 
cluded in  this  concluding  section  of  the  present 
work  has  appeared  as  a  series  of  monographs  is- 
sued by  the  Luther  Burbank  Society  (distributed 
to  its  members  only),  and  is  reproduced  here  by 
courtesy  of  that  organization. 


[xii] 


LUTHER  BURBANK 


PAET  I 

LUTHER  BURBANK  THE  MAN,  AND  AN 
OUTLINE  OF  HIS  METHODS 


CHAPTER  I 

LUTHER  BURBANK:  THE  MAN  AND  HIS 
WORK 

WE  naturally  think  of  Luther  Burbank  as 
a  Calif ornian;  but  in  point  of  fact  the 
celebrated  plant  experimenter  was  born 
and  reared  in  Massachusetts.  The  little  town  of 
Chester  was  his  birthplace,  and  he  grew  to  ma- 
turity on  his  father's  farm  in  daily  contact  with 
nature  in  her  somewhat  primitive  aspects. 

Mr.  Burbank  has  himself  called  attention,  not 
without  amusement,  to  the  fact  that  he  was  his 
father's  thirteenth  child;  and  he  has  used  this 
fact  to  give  whimsical  support  to  his  own  familiar 
method  of  "quantity  production"  in  plant  breed- 
ing, pointing  out  that  no  one  of  the  first  dozen 
children  of  his  fraternity  showed  any  particular 
propensity  to  devote  attention  to  plant  develop- 
ment, and  drawing  therefrom  the  serious  conclu- 
sion that  the  full  potentialities  of  any  hereditary 
strain  cannot  be  realized  unless  the  old-fashioned 
custom  of  having  large  families  is  practiced. 

It  is  a  moral  worth  giving  sober  attention,  in 
these  days  when  the  Colonial  stock,  of  which  Mr. 
Burbank  himself  furnishes  a  rather  typical  ex- 
ample, is  relatively  dwindling,  to  the  detriment — 
at  least  so  some  of  us  think — of  our  civilization. 

[3] 


LWT&ER  BURBANK 

Lnth&r  Surbank  was  a  rather  frail  child,  though 
not  without  abounding  physical  vigor.  He  was 
of  a  thoughtful,  studious  bent  of  mind,  with  an 
inherent  love  of  flowers  and  plants  that  mani- 
fested itself  at  a  very  early  age,  and  with  an 
almost  equally  striking  fondness  for  mechanics. 
It  is  recorded  that  one  of  his  most  fondly  prized 
toys  in  infancy  was  a  specimen  of  spineless  cactus, 
and  that  the  possession  of  a  flower  would  almost 
always  quiet  him  and  give  him,  seemingly,  greater 
pleasure  than  he  derived  from  any  other  kind  of 
toy. 

His  inventive  bent  manifested  itself  very  early, 
and  led  him  to  the  devising  of  many  mechanisms, 
including  a  home-made  steam  engine,  which  he 
used  to  propel  a  boat,  producing  thus  a  prototype 
of  the  modern  motor  boat  half  a  century  before 
that  craft  gained  popularity. 

The  most  conspicuous  application  of  young 
Burbank's  mechanical  genius,  however,  was  made 
in  a  factory  where  he  went  to  work  just  as  he 
was  verging  on  maturity.  This  was  a  labor- 
saving  device  of  such  usefulness  that  it  enabled 
him  to  multiply  the  efficiency  of  his  work  tenfold, 
so  that  his  earnings,  which  at  first  had  amounted 
to  only  fifty  cents  a  day,  quickly  mounted  to  a 
really  respectable  figure.  He  might  have  re- 
mained indefinitely  in  the  factory,  with  the  assur- 
ance of  a  good  salary ;  but  the  confinement  proved 
unhealthful,  and  he  soon  returned  to  the  fields, 
never  thereafter  to  leave  them. 


[4] 


THE  MAN  AND  HIS  WORK 

LUTHER  BURBANK 's  EARLY  EXPERIMENTS 

The  inventive  genius  hitherto  applied  to  me- 
chanical apparatus  was  now  transferred  to  the 
living  plant,  and  from  the  outset  young  Burbank 
began  experimenting  along  new  lines  even  in  car- 
rying out  the  most  commonplace  work  of  the  gar- 
dener. For  instance,  he  found  a  way  to  force  the 
development  of  his  sweet  corn  by  sprouting  the 
seed  in  a  hotbed  and  dropping  the  young  plants 
into  hills  in  the  open  as  if  they  were  mere  seed 
kernels ;  and  he  performed  a  great  variety  of  in- 
teresting experiments  in  the  cross-fertilization  of 
different  races  of  beans,  of  sweet  corn,  and  of 
various  other  garden  products. 

Nothing  strikingly  notable  came  of  this  work, 
however,  until  an  occasion  when  the  experimenter 
discovered  a  seed  ball  on  the  vine  of  an  Early 
Rose  potato;  saved  the  twenty-three  seeds  that 
the  ball  contained,  and  grew  from  each  of  them 
a  hill  of  potatoes  next  season.  The  twenty-three 
hills  were  in  a  single  row,  and  were  given  pre- 
cisely the  same  attention,  yet  each  produced  a 
quite  different  type  of  tuber ;  and  one  of  the  hills 
revealed  a  large  cluster  of  potatoes  of  such  ex- 
ceptional size  and  smoothness  of  contour  and 
quality  of  flesh  as  to  be  very  notable. 

This  was  the  potato  which  the  young  experi- 
menter sold  next  season  to  a  practical  gardener, 
who  gave  it  the  name  of  the  Burbank  potato. 

It  was  estimated  several  years  ago  by  the  au- 
thorities of  the  Department  of  Agriculture  at 

[5] 


LUTHER  BURBANK 

Washington  that  more  than  seventeen  million  dol- 
lars' worth  of  Burbank  potatoes  had  been  raised 
in  the  United  States  since  the  variety  was  intro- 
duced. The  producer  himself  received  only  one 
hundred  and  fifty  dollars  for  his  prize.  The 
money  sufficed,  however,  to  pay  his  fare  across 
the  continent,  and  enabled  him  to  carry  out  his 
ambition  to  migrate  to  a  climate  better  suited  to 
the  purposes  of  the  plant  developer, — for  he  had 
long  since  determined  to  give  his  life  to  this  work. 

THE   MIGEATION   TO    CALIFOKNIA 

Arriving  in  California,  Mr.  Burbank  selected 
Santa  Rosa  as  his  residence,  and  this  has  con- 
tinued to  be  the  seat  of  his  activities  to  this  day. 

The  migration  was  made  in  the  year  1875.  At 
that  time  the  potentialities  of  California  as  a 
fruit-growing  state  were  not  very  fully  realized, 
and  it  was  by  no  means  easy  for  a  young  man 
without  capital  to  establish  himself  in  the  prac- 
tical business  of  a  nurseryman,  which  was  Luther 
Burbank 's  immediate  ambition.  Before  he  could 
carry  out  this  ambition,  it  was  necessary  to  serve 
an  apprenticeship  of  two  or  three  years,  during 
which  he  turned  his  hand  to  any  work  which  pre- 
sented itself.  He  developed  skill  as  a  carpenter, 
and  he  continued  to  earn  a  living  at  that  trade  for 
some  time  after  he  had  established  a  nursery  by 
way  of  avocation. 

Those  were  trying  years;  but  Yankee  thrift, 
energy,  and  perseverance  finally  prevailed  over 

[6] 


THE  MAN  AND  HIS  WORK 

all  obstacles  and  within  four  or  five  years  after 
coming  to  California  Mr.  Burbank  found  himself 
in  possession  of  a  commercial  nursery  that  netted 
him  an  annual  income  of  about  ten  thousand 
dollars.  His  orchard  products  were  mostly  of 
standard  varieties,  but  he  had  applied  to  them 
from  the  outset  the  selective  skill  that  was  to 
make  him  famous,  and  he  had  gained  for  his  seed- 
lings a  reputation  for  reliability  that  caused  them 
to  be  bought  by  would-be  orchardists  throughout 
the  fruit-growing  region. 

Such  commercial  success  as  this  was  gratifying, 
but  Mr.  Burbank  regarded  it  as  only  a  stepping- 
stone.  Even  while  his  chief  time  was  necessarily 
given  over  to  the  practical  duties  of  the  nursery- 
man, he  found  opportunity  to  make  numberless 
experiments  in  hybridization  and  selection  among 
the  various  plants  in  his  nursery ;  and  so  soon  as 
his  financial  affairs  gave  the  least  promise  of  se- 
curity, he  had  cast  about  for  a  piece  of  land  on 
which  he  could  establish  an  experiment  garden 
to  be  devoted  exclusively  to  the  production  of  new 
and  improved  varieties  of  plants  of  every  type. 

He  found  four  acres  that  could  be  made  avail- 
able by  proper  drainage  and  fertilization,  in  the 
town  of  Santa  Rosa,  and  there  he  established  the 
garden  that  was  soon  to  be  famous  as  the  seat  of 
the  most  remarkable  series  of  plant  experiments 
that  have  been  carried  out  in  our  generation.  A 
little  later  he  purchased  a  tract  of  eighteen  acres 
at  Sebastopol,  seven  miles  away,  where  the  topo- 
graphical and  climatic  conditions  were  slightly 

[7] 


LUTHER  BURBANK 

different.  There  his  main  experiment  orchards 
were  established,  and  opportunity  was  afforded 
for  the  carrying  out  of  the  idea  of  "quantity  pro- 
duction" more  effectively  than  was  possible  in 
the  restricted  area  of  the  Santa  Eosa  garden. 

From  that  day  to  this,  Mr.  Burbank  has  con- 
ducted his  experiments  on  these  two  plots  of  land, 
aggregating  about  twenty-two  acres.  Within  this 
relatively  small  area  more  than  a  hundred  thou- 
sand distinct  experiments  have  been  carried  out, 
involving  five  or  six  thousand  species  of  plants, 
and  numberless  varieties,  the  original  seeds  or 
stocks  or  roots  of  which  have  been  sent  to  Mr. 
Burbank  from  all  parts  of  the  world. 

Probably  there  is  no  other  similar  area  of  the 
earth's  surface  that  has  seen  a  corresponding 
variety  of  vegetable  products  in  the  same  time; 
certainly  there  is  no  other  that  in  our  day  has 
produced  such  a  galaxy  of  new  and  wonderful 
plant  products  as  have  grown  in  the  experiment 
gardens  at  Santa  Eosa  and  Sebastopol. 

NEW  APPLICATION   OF   OLD   METHODS 

The  fundamental  principles  of  plant  develop- 
ment through  which  Mr.  Burbank  thought  to  de- 
velop new  and  improved  varieties  were  not  in 
themselves  novel  or  revolutionary.  They  con- 
sisted essentially  in  the  careful  selection  among 
a  mass  of  plants  of  any  individual  that  showed  ex- 
ceptional qualities  of  a  desirable  type ;  the  saving 
of  seed  of  this  exceptional  individual,  and  the 

[8] 


THE  MAN  AND  HIS  WORK 

carrying  out  of  the  same  process  of  selection 
among  the  progeny  through  successive  genera- 
tions. 

Couple  this  method  of  selection  and  so-called 
line  breeding  with  the  method  of  cross-pollenizing 
different  varieties  or  species,  to  produce  hybrid 
forms  showing  a  tendency  to  greater  variation  or 
to  the  accentuation  of  desired  characters,  and  we 
have  in  outline  the  fundamental  principles  of 
plant  breeding  as  known  to  horticulturists  for 
generations,  and  as  applied  by  Mr.  Burbank  from 
the  outset  of  his  career.  But  there  were  sundry 
highly  essential  details  of  modification  that  were 
introduced  by  the  Santa  Rosa  experimenter,  as 
will  appear  presently. 

Moreover,  even  in  the  application  of  the  old 
familiar  method,  Mr.  Burbank  was  able  from  the 
outset  to  gain  exceptional  results  because  of  cer- 
tain inherent  qualities  that  peculiarly  fitted  him 
for  the  work.  Among  these  qualities  was  his  ex- 
ceedingly acute  vision,  a  remarkable  color  sense, 
and  almost  abnormally  developed  senses  of  smell 
and  taste.  Artists  who  have  tested  his  eyes  have 
declared  that  he  can  readily  detect  gradations  of 
color  that  to  the  ordinary  eye  show  no  differentia- 
tion whatever ;  and  it  is  a  matter  of  hourly  demon- 
stration that  he  can  ferret  out  an  individual  flower 
having  any  infinitesimally  modified  odor  in  the 
midst  of  a  bed  of  thousands  of  such  plants,  almost 
as  a  hunting  dog  detects  the  location  of  a  grouse 
or  partridge  under  cover. 

Similarly  his  exquisitely  refined  sense  of  taste 

[9] 


LUTHER  BURBANK 

guides  him  in  selecting  among  thousands  of  in- 
dividual plums  or  cherries  or  grapes  or  apples  or 
berries  the  one  individual  specimen  that  has  the 
most  delectable  flavor  or  that  shows  a  minute 
modification  of  flavor  in  the  direction  in  which 
he  is  endeavoring  to  modify  the  variety. 

This  almost  preternatural  endowment  of  special 
senses  is  supplemented  by  a  knowledge  of  the  co- 
ordination of  parts — say  between  the  stem  or  leaf 
and  the  future  fruit  of  a  plant — that  is  so  pene- 
trating and  mystifying  as  to  seem  intuitional  and 
to  suggest  occult  powers  of  divination. 

As  an  instance,  you  may  see  Mr.  Burbank  strid- 
ing along  a  row  of,  let  us  say,  plum  seedlings  com- 
prising some  thousands  of  plants  perhaps  a  foot 
high.  He  seems  to  inspect  the  little  trees  but 
casually,  except  that  now  and  again  he  pauses  for 
a  moment  to  indicate  with  a  motion  of  his  hand 
that  this  or  that  plant  has  particularly  attracted 
his  attention.  A  helper,  or  more  likely  two 
helpers — for  one  can  scarcely  keep  up  with  the 
energetic  leader — will  be  at  hand  to  note  the  sig- 
nals ;  and  a  bit  of  white  cloth  will  be  tied  about 
each  successively  selected  seedling ;  or  two  pieces 
of  cloth,  or  even  three,  in  case  an  individual  has 
seemed  to  show  quite  exceptional  promise. 

And  with  that,  one  stage  of  the  work  of  selec- 
tion is  finished.  Perhaps  ten  thousand  seedlings 
have  been  passed  in  review  in  a  half-hour,  and 
conceivably  fifty  or  a  hundred  have  been  selected 
for  preservation.  These  have  shown  to  the  keen 
scrutiny  gf  the  plant  experimenter  such  qualities 

[10] 


THE  MAN  AND  HIS  WORK 

of  stem  and  bud  and  leaf  as  to  forecast  the  type 
of  fruit  sought  to  be  developed  in  this  particular 
experiment. 

The  entire  rows  of  seedlings  are  the  product 
of  hybridizing  experiments  and  antecedent  selec- 
tion extending  perhaps  through  many  generations. 
The  seed  from  which  they  were  grown  has  been 
carefully  gathered  and  treasured,  and  infinite 
pains  have  been  taken  to  bring  the  seedlings, 
through  transplantation  and  cultivation,  to  their 
present  stage  of  development. 

Yet  now,  in  a  single  half -hour,  they  have  been 
made  to  run  the  gauntlet  of  a  vision  that  seems 
to  penetrate  to  the  very  heart  of  their  germ-plasm, 
like  an  X-ray,  and  all  but  a  bare  half-dozen  or 
so  in  each  thousand  have  been  found  wanting. 
Another  hour,  and  the  ten  thousand  failures — less 
the  half-hundred — will  have  been  uprooted  and 
piled  in  a  heap  to  be  burned  like  any  other  mass 
of  rubbish.  They  had  done  their  best,  but  their 
best  was  not  good  enough;  and  the  soil  that  they 
occupied  must  be  given  over  to  some  other  line 
of  experiments;  for  every  acre  of  these  gardens 
must  be  made  to  do  the  work  of  a  score  of  acres. 

Meantime  the  dozen  or  score  of  selected  seed- 
lings that  remain  as  the  lone  survivors  here  and 
there  in  the  devastated  ranks  will  be  treasured 
and  be  given  every  horticultural  attention.  At 
the  proper  season  they  will  come  under  the  knife 
of  the  grafter,  who  will  cut  each  stem  into  appro- 
priate sections  and  graft  pieces  on  the  limbs  of 
some  sturdy  tree  of  the  same  species.  This  is 

[11] 


LUTHER  BURBANK 

done  to  hasten  their  development,  for  Mr.  Bur- 
bank  has  discovered  that  stems  thus  grafted  will 
come  to  bearing  much  earlier  than  if  left  on  their 
original  roots.  Time  is  precious,  particularly 
when  we  are  dealing  with  plants  of  such  slow 
growth  as  the  fruit  trees,  and  it  is  obviously  worth 
while  to  save  a  year  or  two,  as  is  thus  possible; 
for  at  best  an  experiment  in  the  development  of 
a  new  type  of  fruit  must  be  carried  out,  as  a 
rule,  through  a  good  many  generations,  making 
significant  encroachments  on  the  working  life  of 
the  plant  experimenter  himself. 

Where  such  a  method  as  that  just  outlined  is 
carried  out,  it  is  obvious  that  everything  depends 
upon  the  skill  with  which  selection  is  made.  A 
man  lacking  Mr.  Burbank's  "intuitional"  skill 
in  such  a  selection  would  inevitably  go  wrong. 
His  experiments  would  come  to  nothing.  He 
would  inadvertently  destroy  the  best  and  preserve 
the  worst.  By  no  mathematical  chance  could  he 
select  the  right  dozen  or  score  of  individuals 
among  the  tens  of  thousands. 

But  that  Mr.  Burbank  is  able  to  make  such  se- 
lections with  a  correctness  that  is  little  less  than 
weird  has  been  demonstrated  again  and  again 
through  tests  in  which  various  of  the  discarded 
seedlings  have  been  preserved  and  brought  to 
fruitage  for  comparison  with  the  selected  ones  of 
their  fraternity. 

Always  the  selected  individuals  show  more  of 
the  quality  that  is  being  sought  than  is  shown  by 
the  specimens  taken  from  the  discard;  thus  jus- 

[12] 


THE  MAN  AND  HIS  WORK 

tifying  a  forecast  that  was  made  so  readily  with 
such  seeming  facility  as  to  appear  almost  necro- 
mantic. 

In  point  of  fact,  the  plant  experimenter  was 
exercising  no  occult  powers  but  only  trained 
senses  backed  by  an  amazing  fund  of  practical 
knowledge.  He  was  looking  for  stems  of  a  par- 
ticular size  and  ruggedness  of  contour ;  for  leaves 
that  were  symmetrical,  right-hued,  and  thrifty; 
for  buds  that  were  plump  and  fat  and  of  just  the 
right  color.  But  his  eye  took  in  the  details  so 
quickly  and  his  conclusions  were  reached  with 
such  seemingly  automatic  precision,  that  the  en- 
tire procedure  took  on  a  mystifying  aspect  of 
wizardry. 

With  such  exhibitions  of  his  skill  constantly  in 
evidence,  it  is  not  strange  that  Mr.  Burbank 
should  have  become  traditional  among  his  own 
contemporaries  as  the  "wizard  of  Santa  Rosa"; 
although  the  worker  himself  has  always  ardently 
deprecated  any  such  characterization,  calling  him- 
self a  "plant  experimenter,"  and  being  foremost 
to  affirm  that  what  he  accomplishes  is  done  by 
careful  study  of  the  laws  of  heredity,  ceaseless 
scrutiny  of  the  physical  qualities  of  plants  in 
their  every  aspect,  and  the  definite  application  of 
knowledge  gained  through  thousands  of  ante- 
cedent experiments. 

The  range  and  scope  of  these  experiments,  it 
may  be  added,  are  no  less  astounding  than  the 
manner  in  which  they  are  carried  out.  There  is 
scarcely  a  tribe  of  plants  showing  any  promise 

[13] 


LUTHER  BURBANK 

whatever  of  development  of  its  stock  or  root  or 
flower  or  fruit  and  having  the  remotest  prospect 
of  thriving  under  the  climatic  conditions  of  Santa 
Rosa  and  Sebastopol  that  has  not  been  tested  by 
specimens  brought  from  one  corner  or  another 
of  the  world — from  both  hemispheres  and  from 
every  continent — and  set  to  work  in  Mr.  Bur- 
bank's  training  school.  To  give  the  names  of  the 
different  species  and  varieties  that  have  here  been 
modified  and  improved  through  selective  breed- 
ing— quite  overlooking  the  other  legions  that  have 
proved  recalcitrant — would  require  many  pages. 
So  I  must  be  content  with  the  citation  of  only  a 
few  of  the  more  conspicuous  examples. 

NEW  FBUITS  FOB   OKCHABD  AND   GAKDEN 

Consider,  for  example,  the  orchard  fruits.  Mr. 
Burbank  has  produced  almost  numberless  new 
varieties  of  apples,  pears,  peaches,  apricots, 
plums,  prunes,  cherries,  and  quinces.  He  has  in- 
troduced more  than  sixty  new  varieties  of  plums 
and  prunes,  combining  the  strains  of  ancestors 
from  Europe  and  Japan  with  those  of  our  native 
species,  and  producing  an  extraordinary  company 
of  fruits  of  the  most  varied  qualities. 

Here,  for  example,  are  prunes  that  are  not  only 
of  gigantic  size  and  borne  in  profusion,  but  which 
have  a  quality  of  ripening  in  midsummer  and 
of  developing  a  greatly  increased  sugar  content. 
Here  are  plums  that  add  to  their  other  qualities 
the  capacity  to  withstand  shipment  across  the  con- 

[14] 


THE  MAN  AND  HIS  WORK 

tinent,  or  for  that  matter  round  the  world.  Here 
is  one  plum  that  looks  and  tastes  like  an  apple 
and  another  that  has  precisely  the  quality  of  a 
Bartlett  pear.  And  here  are  plums  and  prunes 
that  while  exteriorly  looking  like  other  fine  speci- 
mens of  their  kind  differ  essentially  from  all 
others  in  that  you  could  bite  right  through  them 
as  you  bite  through  a  strawberry,  because  they 
are  stoneless. 

And  then,  most  marvelous  of  all,  here  is  a  fruit 
that  had  a  plum  for  one  of  its  ancestors,  but  for 
another  ancestor  an  apricot;  a  strange  hybrid 
which,  in  recognition  of  its  origin,  was  named  the 
"plumcot"  and  which  constitutes  a  brand-new 
type  of  orchard  fruit,  the  first  addition  that  has 
been  made  to  the  familiar  list  within  historical 
times,  and  the  only  orchard  fruit  whose  origin  is 
definitely  known.  This  one  was  created  at  Se- 
bastopol,  as  the  result  of  a  long  series  of  tests 
in  cross-pollenizing  the  plum  and  apricot;  tests 
which  at  first  seemed  doomed  to  failure,  but  which 
ultimately  culminated  in  the  production  of  a  won- 
derful new  fruit. 

In  the  small-fruit  garden,  Mr.  Burbank  has  de- 
veloped many  highly  interesting  new  forms,  some 
of  which  are  entitled  to  rank  as  new  species. 
There  is,  for  example,  the  Primus  berry,  a  cross 
between  the  dewberry  and  the  Siberian  rasp- 
berry; the  Phenomenal  berry,  a  cross  between 
the  dewberry  and  the  Cuthbert  raspberry;  and 
the  Paradox,  a  cross  between  the  Lawton  black- 
berry and  the  crystal  white  blackberry. 

[15] 


LUTHER  BURBANK 

Then  there  are  luscious  blackberries  that  are 
pure  white,  and  others  that  grow  on  vines  that 
are  as  free  from  thorns  as  the  twigs  of  an  apple 
tree. 

Also  there  is  the  sunberry,  a  palatable  fruit 
produced  by  combining  the  traits  of  two  inedible 
nightshades,  and  there  are  numerous  new  varieties 
of  strawberries,  huckleberries,  currants,  gooseber- 
ries, and  elderberries,  as  well  as  sundry  rare  ex- 
otics that  will  claim  our  attention  in  due  course. 

NEW   VEGETABLES   AND   FLOWEES 

In  the  vegetable  garden,  Mr.  Burbank  achieved 
his  earliest  success  through  the  production  of  the 
Burbank  potato,  the  full  story  of  which  will  be 
told  presently.  He  has  worked  effectively  with  all 
the  familiar  types  of  garden  vegetables,  his  efforts 
culminating,  perhaps,  in  the  development  of  the 
now  celebrated  Crimson  winter  rhubarb,  the  an- 
cestor of  which  came  from  New  Zealand. 

Among  thousands  of  experiments  with  flowers 
it  is  hard  to  choose,  so  many  and  so  notable  are 
the  developments.  The  Shasta  daisy,  which  com- 
bines the  strains  of  species  from  Europe,  from 
Japan,  and  from  America,  has  exceptional  inter- 
est both  from  a  scientific  and  from  a  popular 
standpoint.  But  scarcely  less  interesting  are  the 
hybridizing  experiments  through  which  were  pro- 
duced the  giant  amaryllis  with  its  nearly  twelve- 
inch  blossom,  the  spectacular  tigridias,  the  scented 
callas,  dahlias,  and  verbenas,  the  beautiful  wat- 

[16] 


A  GROUP  OF  STONELESS  PLUMS 

The  original  from  which  Mr.  Burhank's  numerous  stoneless  plums 
developed,  is  a  Euronean  fruit  no  larger  than  the  smallest  of  the 
above  specimens.  The  picture  illustrates  the  variation  among  seed- 
lines,  and  the  remarkable  development  in  size  of  the  better  varieties, 
brought  about  through  cross-breeding.  There  is  a  corresponding  im- 
provement in  the  quality  of  the  fruit. 


THE  MAN  AND  HIS  WORK 

sonias  and  gladioli,  the  wonderfully  varied  pop- 
pies, including  one  that  is  blue  in  color,  and  the 
extraordinary  colony  of  lilies  showing  thousands 
of  new  and  strange  combinations  of  form  and 
color. 

By  way  of  adorning  lawn  and  park,  Mr.  Bur- 
bank  has  developed  a  substitute  for  grass  in  the 
South  American  lippia  which  thrives  in  time  of 
drought,  and  requires  not  one-tenth  the  attention 
given  ordinary  lawn  grass.  He  has  developed  a 
vast  number  of  ornamental  shrubs  and  vines,  in- 
cluding new  types  of  clematis  with  beautiful  and 
varied  flowers.  And  in  experimenting  with  trees 
he  has  produced  walnuts  that  grow  to  gigantic 
size  in  a  few  years,  and,  at  the  other  end  of  the 
scale,  chestnuts  that  bear  abundant  crops  when 
they  are  mere  bushes. 

A  chestnut  that  bears  large  nuts  at  six  months 
from  the  seed  creates  as  much  astonishment  as 
almost  any  other  single  anomaly  seen  at  the  fa- 
mous experiment  gardens  at  Sebastopol. 

The  chestnut  that  is  developing  a  smooth  burr 
is  also  of  peculiar  interest;  matching  the  walnut 
that  was  made  to  bear  so  thin  a  shell  that  the 
birds  destroyed  the  nuts,  so  that  it  became  neces- 
sary to  thicken  the  shell  by  further  selective 
breeding. 

These  glimpses,  together  with  bare  mention  of 
the  spineless  cactus  with  its  amazing  crop  of 
luscious  fruit,  must  suffice  to  suggest  the  varied 
lines  of  plant  experiment  that  Mr.  Burbank  car- 
ries forward  year  by  year. 

[17]       v 


LUTHER  BURBANK 

We  shall  have  occasion  to  inquire  just  how  some 
of  these  extraordinary  anomalies  in  plant  life 
were  produced  in  the  course  of  our  examination 
of  the  special  theories  of  plant  development  that 
have  guided  Mr.  Burbank  in  his  elaborate  and 
fruitful  experiments;  and  fuller  details  will  be 
given  in  the  chapters  making  up  Part  II  of  the 
present  volume. 

BURBANK   METHODS  AND   THE   HUMAN   PLANT 

A  man  of  Mr.  Burbank 's  philosophical  cast  of 
mind  could  not  fail  to  give  a  vast  deal  of  thought, 
first  and  last,  to  the  question  of  a  possible  appli- 
cation of  knowledge  gained  in  the  experiment  gar- 
den to  better  development  of  the  human  race.  In 
point  of  fact,  Mr.  Burbank  has  not  only  thought 
but  has  written  and  talked  on  the  subject  very 
extensively.  He  has  very  pronounced  ideas  about 
the  development  of  the  human  plant  that  are  the 
outgrowth  of  his  experimental  studies  with  plant 
life. 

Nowadays  we  all  understand  that  the  same  gen- 
eral principles  apply  to  all  types  of  living  crea- 
tures. With  the  proper  allowance  for  details  of 
variation,  the  laws  of  heredity  studied  in  the  vege- 
table garden  can  be  applied  with  much  assurance 
to  the  breeding  of  animals  or  the  betterment  of 
the  human  race  itself.  So  large  a  subject  cries 
out  for  extended  treatment,  but  it  is  obvious  that 
in  the  space  available  here  I  can  do  no  more  than 
make  brief  reference  to  the  possible  application  of 

[18] 


THE  MAN  AND  HIS  WORK 

the  principles  of  plant  breeding,  as  Mr.  Burbank 
interprets  them  to  the  human  race. 

At  the  very  outset,  we  are  met  with  obvious 
difficulties.  Mr.  Burbank  selected  only  good  stock 
from  which  to  breed.  He  saves  ten  or  a  dozen 
plants  from  a  bed  of  thousands  and  tens  of  thou- 
sands. Obviously  no  such  restriction  is  possible 
in  the  human  family,  even  were  we  to  put  into 
effect  the  most  sweeping  conceptions  of  the 
eugenist. 

But  Mr.  Burbank  optimistically  calls  attention 
to  the  fact  that  the  civilized  races  of  to-day  are 
in  effect  highly  selected  stock.  They  are  the  result 
of  many  centuries  of  breeding  during  which  so- 
ciety endeavored  to  rid  itself  of  undesirables. 
Capital  punishment  for  minor  crimes  doubtless 
had  an  appreciable  eugenic  influence;  and  under 
the  pampering  conditions  of  city  life,  disease 
decimates  the  ranks  of  the  weaklings;  even  wars 
tend  on  the  whole  to  remove  individuals  of  less 
evolved  mentality. 

So,  on  the  whole,  such  a  stock  as  the  average 
American  race  is  a  highly  evolved  and  selected 
type,  in  large  measure  adapted  to  its  environ- 
ment, and  eminently  fit  for  propagating  the 
species. 

But  of  course  some  members  are  better  fitted 
than  others  to  carry  out  this  function;  and  at 
present  there  is  an  unfortunate  tendency  for  the 
better  members  to  have  small  families  while  the 
less  desirable  ones  have  large  families.  It  per- 
haps does  not  need  the  advice  of  the  Santa  Rosa 

[19] 


LUTHER  BURBANK 

experimenter  to  tell  us  that  this  propensity,  if 
not  checked,  must  lead  to  disaster,  but  his  experi- 
ence may  be  cited  as  emphasizing  the  lesson. 

Unless  the  more  desirable  members  of  a  race 
can  be  made  at  least  as  prolific  as  the  less  desir- 
able ones,  that  race  must  deteriorate. 

In  this  connection,  the  enormous  immigration 
of  recent  years,  made  up  largely  of  individuals  of 
a  less  evolved  type  (as  illustrated  by  the  fact  that 
thirty-five  per  cent  of  the  membership  of  the  "new 
immigration"  cannot  read  or  write),  becomes  a 
possible  menace.  Twenty-seven  million  immi- 
grants have  come  to  us  since  1860 — that  is  to  say, 
during  two  generations.  Mr.  Burbank  feels  well 
assured  that  so  large  an  increment  of  new  blood 
must  directly  modify  the  character  of  our  race; 
and  he  is  at  one  with  many  sociologists  in  ques- 
tioning whether  the  increment  of  new  germ-plasm 
has  been,  on  the  whole,  of  a  type  to  prove  bene- 
ficial. 

Of  course  even  an  illiterate  immigrant  might 
bring  certain  qualities — say  a  musical  or  artistic 
sense — that  would  be  advantageous  for  blending 
with  American  racial  strains;  somewhat  as  Mr. 
Burbank 's  inferior  little  French  plum  had  one 
important  quality  of  stonelessness  that  made  it 
valuable.  But  it  must  be  recalled  that  Mr.  Bur- 
bank  was  obliged  to  instil  a  preponderant  influ- 
ence from  valuable  strains  of  plants  to  the  point 
of  entire  elimination  of  the  poor  qualities  of.  the 
original  stoneless  variety.  Without  this  instilla- 
tion of  good  qualities,  he  could  never  have  pro- 

[20] 


THE  MAN  AND  HIS  WORK 

duced  a  stoneless  plum  having  commercial  value. 
Similarly,  it  will  be  necessary  to  overbalance  the 
undesirable  qualities  of  the  unevolved  immigrant 
by  a  preponderance  of  good  blood  if  we  are  to 
make  use  of  his  desirable  qualities. 

From  this  point  of  view,  then,  the  same  ques- 
tion is  emphasized:  The  better  stock  of  America 
must  be  induced  to  reproduce  itself  more  abun- 
dantly than  has  been  its  custom  of  late,  or  the 
infusion  of  immigrant  blood  of  the  type  that  is 
coming  to  us  will  be  ultimately  harmful. 

As  to  the  rearing  of  the  human  plant  in  its 
early  stages — that  is  to  say,  the  care  of  the  child 
— Mr.  Burbank  has  ideas  that  are  equally  pro- 
nounced; and  here  he  is  able,  perhaps,  to  make 
more  directly  tangible  applications  of  his  studies 
in  the  field.  As  a  practical  horticulturist,  he  has 
been  called  upon  thousands  of  times  over  to  ob- 
serve that  everything  depends  upon  the  treatment 
that  the  seedling  receives  the  first  few  days  or 
weeks  of  its  life.  He  takes  infinite  pains  to  pro- 
vide just  the  right  soil,  just  the  right  conditions 
of  moisture  and  sunlight  and  shelter  from  the 
wind;  and  he  has  seen  it  demonstrated  times  with- 
out number  that  the  weal  or  woe  of  the  future 
plant,  whatever  its  heredity,  is  largely  determined 
by  this  early  treatment. 

Making  application  to  the  human  plant,  he  be- 
lieves that  few  people  fully  understand  how 
largely  the  body  and  mind  of  the  child  are  molded 
by  the  environing  influence  of  infancy.  He  urges 
very  strenuously  that  life  should  be  made  agree- 

[21] 


LUTHER  BURBANK 

able  for  the  young  child;  that  it  should  be  kept 
in  the  open,  allowed  to  play,  to  come  in  contact 
with  nature,  to  do  the  things  in  which  childhood 
naturally  delights. 

He  would  have  no  child  sent  to  school  until  it 
is  nine  or  ten  years  old,  believing  that  the  educa- 
tion of  the  playground  and  field  is  better  than  the 
education  of  the  schoolroom  during  this  early 
period. 

And  when  the  child  has  reached  the  school  age, 
he  would  have  its  tasks  made  less  laborious  and 
exacting  than  they  sometimes  are. 

He  would  pay  heed  at  all  stages  to  the  child's 
bodily  development,  knowing  that  fine  blossoms 
do  not  come  from  dwarfed  plants. 

In  a  word,  he  would  make  the  environment  of 
childhood  and  adolescence  healthful  and  stimu- 
lative and  pleasure-giving — comparable  to  the  en- 
vironment that  he  supplies  for  his  seedling  plants. 
Only  by  doing  as  he  does  can  Mr.  Burbank  secure 
the  best  results  with  his  plant  proteges ;  andxonly 
by  a  comparable  line  of  action,  in  our  treatment 
of  the  child,  so  he  believes,  can  we  count  on  mak- 
ing the  most  of  the  coming  human  generation. 

Mr.  Burbank 's  love  of  children  is  comparable 
to  his  love  of  flowers.  It^was^  peculiarlyappro- 
priate  that  the  Legislature  of 
have  sH^^e^JiOiHEdS^lhe  ninth_of^tarch, 
as  a  school  holiday  to  be  known^s  j?orbank  Pay. 
On  that  day  each  successive  year  the  school  chil- 
dren of  Santa  Rosa"  come  to  pay  their  respects  to 
Mr.  Burbank  in  jperson ;  and  he  has  received  as 

[22] 


THE  MAN  AND  HIS  WORK 

many  as  four  thousand  letters  at  once  congratu- 
lating him  on  the  occasion  from  the  school  chil- 
dren of  other^  cities  and  even  of  distant  states. 

To  see  Mr.  Burbank  on  his  doorstep  sur- 
rounded by  a  group  of  school  children  is  to  see 
him  as  happy  as  when  he  is  in  his  garden  amidst 
beds  of  rare  and  beautiful  flowers.  No  sketch 
of  the  Santa  Rosa  plant  developer  would  be  com- 
plete that  did  not  refer  to  this  aspect  of  his  inter- 
ests and  give  emphasis  to  this  phase  of  his  per- 
sonality. 

In  Part  III  of  the  present  volume  we  shall  have 
occasion  to  treat  somewhat  in  detail  the  question 
of  the  possible  application  of  Burbank  methods 
and  allied  biological  data  to  the  improvement  of 
the  human  plant.  But  we  must  first  study  the 
methods  themselves  and  their  direct  application 
in  the  gardens  of  the  Santa  Eosa  experimenter. 


[23] 


CHAPTER  II 
THEORIES  OF  PLANT  DEVELOPMENT 

FIRST,  last,  and  all  the  time  Mr.  Burbank  is 
a  practical  plant  developer.  But  it  would 
have  been  quite  out  of  the  question  for  a 
man  of  his  energetic  and  active  type  of  mind  to 
have  gone  about  his  experiments  without  theoriz- 
ing constantly  as  to  the  whys  and  wherefores  of 
the  intricate  life  forces  with  which  he  was  dealing. 

In  point  of  fact,  it  is  as  natural  for  Mr.  Bur- 
bank  to  theorize  as  it  is  for  him  to  make  practical 
experiments.  His  mind  is  no  less  incessantly 
active  than  his  body,  and  his  views  on  the  theories 
that  underlie  plant  development  are  as  pro- 
nounced and  radical  as  are  his  opinions  concern- 
ing practical  matters  of  horticulture  and  plant 
management  in  the  fields,  regarding  which,  doubt- 
less, he  has  had  a  larger  personal  experience  than 
any  other  man  in  the  world. 

In  briefly  outlining  Mr.  Burbank 's  attitude  to- 
ward various  of  the  moot  points  of  heredity,  it 
will  be  convenient  to  call  attention  to  a  few  typical 
instances  of  his  own  experiments  that  give  sup- 
port to  his  views. 

(1)  First  as  to  the  broad  general  question  of 
Darwinian  evolution.  When  a  very  young  man 
Mr.  Burbank  read  with  avidity  Darwin's  then  re- 

[24] 


A  FRUIT-BEARING   SLAB  OF  SPINELESS  CACTUS 

The  particular  slab  here  shown  is  merefy  an  average  specimen.  Number- 
less slabs  in  the  same  field  bear  two  or  three  times  as  many  individual  fruits. 
A  slab  has  been  known  to  bear  as  many  as  150  of  these  "  Cactus  pears." 


THEORIES  OF  DEVELOPMENT 

cently  issued  work,  Animals  and  Plants  under  Do- 
mestication, and  at  once  he  began  making  personal 
scrutiny  of  all  the  plants  of  his  neighborhood,  and 
was  struck  with  the  fact  of  universal  variation 
both  in  the  wild  state  and  under  cultivation. 

From  the  outset,  his  experiments  had  to  do 
with  selection  between  individual  specimens  that 
differ  in  some  measure  from  their  fellows,  and  at 
every  stage  of  his  work  such  a  selection  continues. 
"The  beginning  is  selection  and  the  end  is  selec- 
tion," declares  Mr.  Burbank;  and  the, possibility 
of  developing  new  races  of  many  types  from  a 
single  stock  through  selection  alone  has  been 
demonstrated  by  him  thousands  of  times  over. 

As  Burbankian  selection  is  after  all  only  nat- 
ural selection,  in  which  a  man's  wishes  become  the 
chief  determining  agent  among  environmental  in- 
fluences, it  may  fairly  be  said  that  the  demon- 
strations made  over  and  over  at  Santa  Eosa  have 
supplied  the  largest  body  of  evidence  for  the  truth 
of  the  doctrine  of  evolution  through  natural  selec- 
tion that  has  anywhere  been  made  available. 

After  studying  Mr.  Burbank 's  results,  it  is  im- 
possible to  doubt  that  natural  selection  has  been 
at  least  one  highly  important  agency  in  shaping 
the  evolution  of  the  living  races. 

As  an  instance  of  the  way  in  which  new  races 
may  be  rapidly  developed  by  artificial  selection 
alone,  we  may  cite  the  case  of  the  half-dozen  new 
varieties  of  garden  peas,  differing  radically  from 
one  another,  and  each  breeding  true  to  its  own 
kind,  that  were  developed  by  Mr.  Burbank  in  the 

[25] 


LUTHER  BURBANK 

course  of  six  generations  from  a  single  parent 
form. 

The  new  variety  of  heuchera,  or  "wild  gera- 
nium," with  its  amazingly  corrugated  and  convo- 
luted leaf,  furnishes  another  example  of  extraor- 
dinary modification  of  form  brought  about  by 
merely  selecting  the  seed  of  an  individual  that 
showed  a  tendency  to  modification,  and  carrying 
on  the  selection  through  several  successive  gen- 
erations. 

That  the  same  principle  applies  equally  to  the 
modification  of  stalk  or  root  or  bulb  or  flower  or 
fruit  of  plants  of  every  type  has  been  demon- 
strated so  many  times  over  in  Mr.  Burbank's 
experience  that  to  cite  his  proof  of  the  proposition 
in  its  entirety  would  be  equivalent  to  naming  all 
the  hundreds  of  new  varieties  that  he  has  devel- 
oped. For  the  cases  are  few  indeed  in  which  the 
principle  of  selection  has  not  been  applied  at  some 
stage  of  the  experiment.  Even  where  hybridiza- 
tion has  played  an  important  part,  it  is  of  course 
necessary  first  to  select  the  parents  for  crossing; 
and  then,  in  due  course,  selection  is  made  again 
among  the  progeny. 

So  it  may  be  repeated  that  artificial  selection 
is  the  keynote  to  plant  development ;  and  that  the 
experiments  at  Santa  Rosa  and  Sebastopol  fur- 
nish an  unending  series  of  demonstrations  as  to 
the  way  in  which  nature  works  in  the  bringing 
about  of  evolution  of  races  through  natural  selec- 
tion and  the  survival  of  the  fittest. 

(2)  As  to  the  question  of  the  transmissibility 
[26] 


THEORIES  OF  DEVELOPMENT 

of  acquired  characters,  Mr.  Burbank  answers  em- 
phatically in  the  affirmative.  As  he  sees  the  mat- 
ter, all  traits  of  every  species  were  at  some  time 
acquired  in  response  to  environmental  stimuli. 
To  deny  the  transmissibility  of  new  traits  thus 
acquired  from  time  to  time  in  the  geological  ages 
would  be  tantamount  to  denying  evolution  itself. 
He  finds  that  plants  of  closely  related  species 
brought  from  different  continents  transmit  their 
qualities  when  interbred;  and  he  has  little  pa- 
tience with  the  modern  quibble  which  would  admit 
the  transmissibility  of  qualities  imprinted  directly 
on  the  germ-plasm,  while  denying  transmissibility 
of  the  changes  in  the  body-plasm,  in  view  of  the 
fact  that  the  germ-plasm  itself  is  part  of  the  plant 
body  and,  moreover,  is  apparently  disseminated 
everywhere  throughout  the  plant  organism,  inas- 
much as  individual  buds  or  pieces  of  stalk,  or  bits 
of  root  or  bulb,  may  in  numberless  instances  re- 
produce the  entire  plant  quite  as  effectively  as  it 
is  reproduced  from  the  seed. 

In  thus  advocating  the  theory  of  the  universal- 
ity of  acquired  traits,  however,  Mr.  Burbank  of 
course  does  not  refer  to  gross  lesions ;  and  it  may 
be  added  that  he  has  not  personally  conducted  any 
experiments  in  the  attempted  modification  of  the 
germ-plasm  through  use  of  chemicals  or  of  radium 
such  as  some  other  workers  are  now  undertaking. 


[27] 


LUTHER  BURBANK 

THE   OEIGIN   OF   THE  FITTEST 

(3)  As  to  the  origin  of  the  variations  observed 
in  nature,  which  supply  the  material  for  the  opera- 
tion of  natural  selection,  Mr.  Burbank  has  very 
pronounced  ideas.  He  believes  that  the  usual 
cause  of  such  variation  is  hybridization  between 
different  species  or  varieties.  One  of  his  earliest 
discoveries  was  that  by  crossing  divergent  races 
or  totally  different  species  he  could  produce  hy- 
brids that  were  different  from  either  parent,  and 
that  sometimes  these  hybrids  breed  true. 

A  striking  illustration  of  this  was  furnished 
when  he  cross-pollenized  a  raspberry  brought 
from  Siberia  with  a  California  dewberry — a 
species  of  trailing  blackberry.  The  result  was  a 
berry  of  a  new  type,  differing  radically  from 
either  parent,  which  seems  entitled  to  rank  as  a 
new  species,  inasmuch  as  it  has  its  own  type. 

Another  illustration  of  the  production  of  a  new 
species  by  hybridizing  is  found  in  Mr.  Burbank 's 
Phenomenal  berry,  the  product  of  a  union  between 
the  Cuthbert  raspberry  and  the  California  dew- 
berry. Yet  others  are  the  plumcot,  already  re- 
ferred to;  the  extraordinary  Paradox  walnut, 
which  combines  the  strains  of  the  Persian  walnut 
and  the  California  black  walnut;  and  the  Shasta 
daisy,  combining  the  strains  of  a  European,  an 
American,  and  a  Japanese  species,  and  itself  dif- 
fering very  radically  from  any  one  of  its  an- 
cestors. 

Mr.  Burbank  has  found  many  instances  of 
[28] 


THEORIES  OF  DEVELOPMENT 

hybridization  in  a  state  of  nature.  He  has,  for 
example,  seen  hybrid  raspberries  growing  wild 
and  maintaining  their  own  in  the  same  neighbor- 
hood with  both  of  their  parents.  The  same  thing 
occurs  in  the  case  of  a  species  of  madder  that 
grows  abundantly  along  the  roadsides  near  Se- 
bastopol.  Mr.  Burbank  has  seen  nuts  that  he  be- 
lieves to  be  a  natural  cross  between  the  pecan  and 
hickory.  In  a  word,  he  believes  that  hybridization 
among  wild  species  is  an  exceedingly  common  phe- 
nomenon, and  that  this  is  at  least  one  of  the  prom- 
inent means  of  developing  new  species  and  new 
varieties  upon  which  natural  selection  may  work 
differentiation  of  species. 

Mr.  Burbank  thus  supplements  and  extends  the 
Darwinian  theory,  offering  what  seems  the  best 
explanation  hitherto  suggested  of  the  "origin  of 
the  fittest,"  about  which  Darwin  himself  and  his 
chief  disciples  were  very  much  in  the  dark. 

It  should  be  added  that  Mr.  Burbank 's  experi- 
ments, while  showing  in  numberless  cases  the 
possibility  of  the  development  of  new  varieties 
through  cross-breeding,  show  also  the  limitations 
that  nature  puts  upon  the  method  by  denying  fer- 
tility to  hybrids  that  result  from  the  crossing  of 
parents  too  widely  divergent.  For  example,  he 
made  an  extraordinary  series  of  cross-pollenizing 
experiments  in  which  the  strains  of  many  mem- 
bers of  the  rose  family,  including  the  apple,  the 
pear,  the  mountain  ash,  and  the  rose  itself,  were 
blended  with  those  of  the  blackberry.  Similarly 
he  crossed  the  raspberry  and  the  strawberry, 

[29] 


LUTHER  BURBANK 

also  the  pear  and  the  apple,  the  pear  and  the 
quince,  and  the  quince  and  the  apple;  and  yet 
again,  the  petunia  and  the  tobacco,  and  the  crinum 
and  the  amaryllis.  But  in  each  of  these  cases, 
while  very  interesting  hybrids  were  produced, 
they  were  entirely  sterile,  and  the  experiment 
could  go  no  further. 

Sometimes  species  are  crossed  that  are  just 
widely  enough  divergent  so  that  the  offspring  are 
relatively  infecund  but  not  actually  sterile.  Such 
was  the  case  with  the  cross  between  the  Persian 
and  the  California  walnut,  the  offspring  of  which 
is  a  tree  of  enormously  rapid  growth,  but  bearing 
only  a  handful  of  nuts;  whereas  another  walnut 
cross,  that  between  the  American  black  walnut  of 
the  East  and  the  California  black  walnut,  is  enor- 
mously prolific,  bearing  bushels  of  nuts  where  the 
other  hybrid  bears  only  individual  specimens. 

The  celebrated  cross  between  the  plum  and  the 
apricot  furnished  interesting  illustrations  of  the 
same  thing.  Most  of  the  hybrids  thus  produced 
bore  imperfect  flowers  lacking  petals  or  stamens 
or  pistils,  as  the  case  might  be.  It  was  only  after 
many  efforts  a  specimen  was  produced  that  was 
fertile,  yet  ultimately  the  race  of  hybrid  plum- 
cots  was  so  developed  that  it  now  has  many  varie- 
ties, some  of  them  being  excessively  prolific.  Yet 
another  instance  of  the  way  in  which  the  barriers 
between  species  may  be  broken  down  by  persistent 
effort  (through  ultimately  finding  plants  having 
just  the  right  degree  of  affinity)  is  that  in  which 
Mr.  Burbank  produced  the  sunberry  by  crossing 

[30] 


THEORIES  OF  DEVELOPMENT 

two  species  of  solaimm,  that  he  had  attempted 
ineffectually  to  cross  from  time  to  time  for 
twenty-five  years,  success  finally  coming  in  the 
form  of  a  single  fertile  seed  case. 

MENDELIAN   HEEEDITY 

(4)  As  to  later  progress  of  hybrid  races. 
Whereas  sometimes,  in  case  of  the  Primus  berry, 
a  hybrid  shows  a  combination  of  the  traits  of  the 
parents,  constituting  a  new  type  that  breeds  true, 
this  is  not  the  usual  result  of  crossing  different 
species  or  marked  varieties.  As  a  rule,  the  hybrid 
shows  a  tendency,  as  regards  any  given  character, 
to  follow  one  parent  to  the  exclusion  of  the  other. 
If,  for  example,  you  can  cross  a  stoneless  plum 
with  an  ordinary  plum,  you  must  expect  that  all 
the  progeny  will  bear  stone  fruit. 

But  Mr.  Burbank  early  made  the  discovery  that 
if  hybrid  forms  are  allowed  to  interbreed,  their 
progeny  usually  show  an  extraordinary  tendency 
to  variation,  some  of  them  reverting  in  one  direc- 
tion and  some  in  another,  and  some  individuals 
combining  the  traits  of  the  two  divergent  lines 
of  ancestry  in  new  combinations.  He  discovered 
that  the  best  opportunity  was  afforded  for  the 
development  of  new  types ;  and  he  eagerly  put  this 
discovery  to  account  in  numberless  breeding  ex- 
periments. 

Now  this  discovery,  made  by  Mr.  Burbank  in 
the  early  eighties,  is  essentially  the  discovery  that 
had  been  made  twenty  years  before  by  Gregor 

[31] 


LUTHER  BURBANK 

Mendel,  the  Austro-Silesian  monk,  to  which  no 
one  paid  any  attention  until  long  afterwards. 

After  Mendel  died  in  1884,  there  was  an  interval 
of  about  sixteen  years,  prior  to  his  rediscovery 
and  the  posthumous  promulgation  of  his  doctrines 
by  Professor  De  Vries  and  others,  during  which 
Mr.  Burbank  was  probably  the  only  man  in  the 
world  who  had  any  clear  conception  of  the  essen- 
tial facts  of  the  segregation  and  recombination  of 
characters  in  the  second  filial  generation  of  cross- 
bred races.  Mr.  Burbank  did  not  make  mathe- 
matical tests  in  connection  with  his  experiments, 
as  Mendel  had  done ;  but  he  demonstrated  the  gen- 
eral truth  of  what  has  since  come  to  be  known 
as  Mendelian  inheritance  thousands  of  times  over 
in  the  course  of  his  independent  experiments  at  a 
time  when  neither  he  nor  anyone  else  had  so  much 
as  heard  the  name  of  Mendel. 

It  was  by  application  of  his  independent  dis- 
covery of  the  principle  of  the  segregation  and  re- 
combination of  parental  characters  in  the  second 
and  subsequent  generations  that  most  of  his  re- 
markable new  varieties  and  new  species  were 
developed. 

Thus  the  commercial  races  of  stoneless  plums 
and  prunes  were  produced  through  blending  the 
strains  of  a  little  partially  stoneless  European 
plum  that  was  not  much  bigger  than  a  cranberry, 
and  was  acrid  and  worthless,  with  the  strains 
of  numerous  choice  varieties  of  cultivated  plums 
through  successive  generations,  each  immediate 
cross  resulting  in  stone  fruit;  and  the  quality  of 

[32] 


•,:,  * 


MR.    BURBANK    INSPECTING    A    CHOICE    VARIETY    OF    SPINELESS 

CACTUS 

The  picture  was  taken  in  the  season  of  1914.  The  bed  of  young 
spineless  cactus  plants  here  shown  includes  some  of  the  most  perfect 
specimens  hitherto  developed.  They  grow  in  the  garden  at  Santa  Rosa. 


THEORIES  OF  DEVELOPMENT 

stonelessness,  in  combination  with  other  desirable 
qualities  from  divergent  strains,  reappearing  only 
in  the  subsequent  generations. 

Altogether  similar  was  the  history  of  the  thorn- 
less  blackberry,  which  finally  developed  into 
a  wonderfully  vigorous  plant  with  stems  as 
smooth  as  pussy-willows,  and  bearing  an  abun- 
dance of  luscious  fruit,  is  the  product  of  many 
generations  of  cross-breeding  through  which  the 
quality  of  thornlessness  that  was  inherent  in  a 
little  otherwise  worthless  trailing  dewberry  from 
Virginia  was  combined  with  the  good  qualities  of 
sundry  varieties  of  cultivated  blackberries  that 
grew  on  thorn-laden  bushes. 

The  development  of  the  white  blackberry,  from 
a  small  variety  of  brownish- white  color  to  a  splen- 
did berry  of  snowy  whiteness,  came  about  in  the 
same  way;  and  to  this  day,  if  you  were  to  cross 
an  ordinary  blackberry  with  the  Burbank  white 
variety,  you  must  expect  that  the  progeny  will 
bear  black  berries,  and  only  in  the  succeeding 
generation  will  plants  appear  that  bear  the  white 
fruit  of  one  of  their  grandparents. 

SELECTIVE  LINE  BKEEDING 

(5)  The  accentuation  of  characters  by  line 
breeding  plays  a  no  less  significant  part  in  Mr. 
Burbank 's  scheme  of  plant  development.  Whether 
the  plant  with  which  you  deal  be  pure  breed  of 
a  hybrid,  it  will  seldom  happen  that  a  quality 
that  you  are  attempting  to  develop  is  manifested 

[33] 


LUTHER  BURBANK 

in  superlative  degree.  It  may  be,  indeed,  that  the 
desired  quality  appears  only  as  a  faint  trace  or 
suggestion. 

Such  was  the  case,  for  example,  with  a  certain 
specimen  of  the  calla  in  which  Mr.  Burbank  de- 
tected a  faint  trace  of  a  pleasant  perfume.  He 
carefully  preserved  the  seeds  of  that  calla,  and 
by  similarly  selecting  among  the  descendants  he 
produced  a  race  of  perfumed  callas.  In  the  same 
way  he  produced  scented  petunias  and  verbenas 
that  have  gained  great  popularity. 

Again,  Mr.  Burbank  once  found  a  specimen  of 
the  California  poppy  that  had  a  faint  line  of  red 
extending  down  one  of  its  golden  petals.  This 
specimen  was  transplanted  and  treasured.  Among 
its  progeny  was  a  specimen  that  showed  a  slightly 
more  conspicuous  red  line  on  a  petal  of  one  of 
its  flowers.  The  seed  of  this  specimen  was  pre- 
served ;  and  so  on  generation  after  generation,  the 
tendency  to  red  being  accentuated  in  a  few  indi- 
viduals in  each  generation;  until  finally  a  new 
variety  of  poppy  had  been  produced  in  which  the 
normal  golden  color  had  disappeared  altogether, 
and  the  entire  flower  was  of  a  bright  crimson — 
justifying  the  name  of  "Fireflame"  that  was 
given  it. 

The  Santa  Rosa  Shirley  poppy,  with  its  deli- 
cately crenated  petals;  the  silver-lining  poppy, 
with  the  inner  surface  of  its  petals  transformed 
from  red  to  white,  and  the  wonderful  blue  poppy, 
selected  out,  through  generations  of  breeding,  as 
the  remote  descendant  of  an  individual  red  poppy 

[34] 


THEORIES  OF  DEVELOPMENT 

whose  petals  showed  a  trace  of  cloudiness,  are 
other  striking  examples  of  the  accentuation  of  a 
character  through  line  breeding. 

The  sturdy  winter  rhubarb  has  been  developed 
in  the  same  way  from  the  plant  imported  from 
New  Zealand  with  a  stem  no  larger  than  a  pencil. 
The  absolutely  smooth  cactus  is  the  descendant 
of  plants  that  only  showed  a  tendency  to  be  some- 
what less  spiny  than  their  fellows. 

CREATION   OR   RECRUDESCENCE 

An  interesting  question  arises  as  to  whether 
such  accentuation  of  a  peculiarity  or  tendency 
may  amount  to  the  bringing  out  of  a  new  char- 
acter that  was  not  represented  in  any  ancestor, 
near  or  remote. 

Is  Mr.  Burbank's  light  blue  poppy,  for  example, 
the  first  of  its  kind;  or  were  there  blue  flowers 
among  some  of  the  ancestors  of  the  poppy? 

The  best  view  appears  to  be  that  the  seemingly 
new  trait  was  really  submerged  in  the  ancestral 
germ-plasm,  if  the  phrase  be  allowed,  and  has 
been  made  tangible  by  the  removal  of  more  or 
less  antagonistic  traits  that  obscured  it.  In  the 
case  of  the  blue  poppy,  for  example,  the  sub- 
mergence was  doubtless  of  long  duration,  for  blue 
poppies  have  not  been  in  fashion  within  the  mem- 
ory of  man;  but  through  successive  generations 
of  selection  the  factors  for  redness  and  yellow- 
ness were  removed,  and  an  individual  finally  pro- 
duced in  which  the  primal  blue,  which  was  prob- 

[35] 


LUTHER  BURBANK 

ably  the  color  of  some  very  remote  ancestral 
poppy,  was  revealed.  In  a  crude  general  way,  the 
process  might  be  compared  to  the  restoration  of 
an  ancient  canvas  by  the  removal  of  successive 
layers  of  pigment  with  which  it  has  been  overlaid. 

THE   COLORS   OF   FLOWERS   EXPLAINED 

While  the  colors  of  flowers  are  under  consid- 
eration, it  may  be  well  to  say  a  word  about  a 
theory  as  to  flower  coloration  that  may  sometimes 
prove  helpful  in  carrying  out  a  line  of  experi- 
ments; the  theory,  namely,  that  all  flowers  were 
originally  green  and  that  as  evolution  progressed 
they  varied  up  and  down  the  chromatic  scale, — 
some  lines  of  descent  producing  successive  blue 
and  indigo  and  violet  flowers,  while  other  lines 
of  descent  produced  yellow  and  orange  and  red 
flowers  instead. 

If  we  hold  that  hereditary  factors  once  acquired 
by  any  race  are  never  altogether  lost  from  the 
germ-plasm  of  that  race,  it  would  follow  that  all 
red  flowers  have  the  potentialities  of  orange  and 
yellow  in  their  heredity,  and  that  all  violet  flowers 
have  the  potentialities  of  indigo  and  blue. 

Moreover,  since  there  would  have  been  cross- 
breeding at  all  stages  of  development,  it  may 
fairly  be  assumed  that  there  are  strains  of  blue 
as  well  as  of  orange  and  yellow  in  the  red  flower ; 
also  strains  of  blue  in  the  yellow  flower,  and 
strains  of  yellow  in  the  red  flower. 

There  is  some  evidence  to  show  that  white  flow- 
[36] 


THEORIES  OF  DEVELOPMENT 

ers  may  be  due  to  a  blending  of  pigments — say  a 
mixture  of  yellow  and  blue.  White  may  also  be 
due  to  a  prismatic  effect  induced  by  the  presence 
of  air  spaces  between  the  cells. 

It  is  fairly  .clear  that  different  colors  may  be 
advantageous  for  the  flower  according  to  the 
mode  of  growth  of  the  plant  on  which  the  flower 
is  borne.  Thus  plants  that  grow  in  the  shadow 
and  those  that  bloom  in  the  evening  advan- 
tageously bear  white  or  pale  yellow  flowers,  as 
these  are  more  conspicuous  than  the  most  gaudily 
hued  flower  would  be  under  the  circumstances. 
On  the  other  hand,  a  plant  that  grows  in  the  open 
may  bear  a  red  flower  both  because  that  color  will 
be  attractive  to  insects  that  fertilize  the  flower 
and  because  the  reflection  of  the  long  waves  of 
light  (giving  our  eye  the  impression  of  red)  serves 
to  shield  the  petals  from  excessive  heat. 

If,  then,  most  flowers  have  the  potentialities  of 
wide  color  variation,  there  is  opportunity  for  the 
play  of  natural  selection  in  adapting  each  flower 
to  the  environment  in  which  the  plant  on  which  it 
grows  flourishes  to  best  advantage. 

This  theory  of  flower  coloration  finds  a  measure 
of  support  in  another  theory  which  attempts  to 
explain  the  peculiar  phenomena  of  "  dominance ' ' 
and  "recessiveness"  as  manifested  in  Mendelian 
heredity.  According  to  this  explanation,  where 
two  antagonistic  characters  thus  Mendelize,  the 
one  that  is  dominant  is  the  newer  character  and 
the  one  that  is  recessive  is  the  older.  This  pre- 
cisely reverses  the  view  that  has  been  suggested 

[37] 


LUTHER  BURBANK 

by  some  biologists,  but  there  is  a  large  amount  of 
evidence  to  support  it. 

To  illustrate  from  the  case  in  point,  it  appears 
that,  as  a  rule,  when  red  flowers  are  crossed  with 
flowers  of  another  color,  say  white,  the  red  tends 
to  prove  dominant.  Similarly,  when  a  white 
poppy  is  crossed  with  Mr.  Burbank's  blue  one, 
the  progeny  are  white.  This  is  consistent,  at 
least,  with  the  theoretical  assumption  that  new 
characters  dominate  old  ones,  and  that  red  is  the 
newest  flower  color  and  white  a  newer  color  than 
blue. 

I  must  not  claim  space  to  elucidate  either  theory 
in  detail  here.  But  I  may  point  out,  in  passing, 
that  the  theory  that  new  strains  are  dominant  to 
older  ones  aids  us  sometimes  in  the  interpretation 
of  the  observed  results  of  experiments  in  plant 
breeding.  We  should  expect,  for  example,  that 
the  spines  would  be  dominant  to  spinelessness  in 
ease  of  the  blackberry  and  cactus,  for  it  may  be 
assumed  that  the  spines  were  a  comparatively 
recent  development  in  the  evolutionary  scale. 
Again,  pigment  would  be  dominant  to  lack  of  pig- 
ment in  the  blackberry;  for  the  fact  that  the 
young  berries  are  colorless  or  green  strongly  sup- 
ports the  assumption  that  the  primordial  an- 
cestors of  the  blackberry  bore  colorless  fruit. 

FIXING   CHAEACTEKS 

In  a  slightly  different  connection  it  may  be 
noted  that  study  of  dominance  and  recessiveness 

[38] 


THEORIES  OF  DEVELOPMENT 

in  plant  characters  is  of  the  utmost  practical  im- 
portance for  the  plant  developer  as  an  aid  in  fix- 
ing characters  so  that  they  will  breed  true,  often 
a  task  of  great  difficulty. 

This  does  not  matter,  of  course,  in  the  case  of 
orchard  fruits,  which  are  propagated  by  grafting, 
and  of  various  bulbous  and  other  plants  that  are 
propagated  by  root  division.  But  in  case  of  an- 
nuals grown  from  the  seed  it  is  highly  important 
that  a  new  desirable  character  should  be  fixed  in 
such  a  way  that  it  will  be  reproduced  in  the 
progeny. 

Now  according  to  the  Mendelian  formula,  in  its 
simplest  terms,  where  any  pair  of  antagonistic 
characters  that  Mendelize  are  in  question,  the  re- 
cessive character  which  disappears  absolutely  in 
the  first  filial  generation  will  reappear  tangibly 
in  one  in  four  of  the  offspring  of  the  second  gen- 
eration, and  will  be  submerged  in  the  germ-plasm 
of  two  others  of  each  group  of  four,  the  remaining 
member  of  the  group  being  a  pure  dominant. 

To  illustrate  from  Mendel's  careful  experi- 
ments, when  a  tall  and  a  short  variety  of  garden 
pea  are  crossed,  all  the  progeny  are  tall;  but  in 
the  next  generation  one  specimen  in  four  is  short 
and  the  other  two  specimens,  while  individually 
tall,  have  the  factors  for  shortness  submerged  in 
their  germ-plasm.  The  short  specimen  being 
purely  recessive  will  breed  true  to  shortness ;  but 
the  two  tall  specimens  that  are  mixed  will  not 
breed  true. 

The  same  principle  holds  for  any  pair  of  an- 
[39] 


LUTHER  BURBANK 

tagonistic  characters  that  show  the  phenomena  of 
dominance  and  recessiveness. 

It  follows  that  if  a  character  which  you  are 
striving  to  fix  in  any  given  experiment  is  a  re- 
cessive character,  it  is  fixed  from  the  moment 
when  it  reappears  and  you  may  give  yourself  no 
further  concern  in  the  matter.  But  if  it  be  a 
dominant  character,  then  you  must  be  on  the  look- 
out, since  of  every  three  specimens  that  show  the 
character,  two  will  have  factors  for  the  antag- 
onistic character  in  their  germ-plasm,  and  do 
not  constitute  fixed  strains.  Only  by  watching 
through  another  generation  can  it  be  determined 
which  individuals  are  "pure  dominants,"  and 
such  alone  will  breed  true. 

Until  the  Mendelian  formula  was  known  breed- 
ers were  often  put  to  their  wits'  end  to  segregate 
a  strain  that  would  breed  true ;  whereas  now,  with 
the  formula  in  mind,  this  may  usually  be  accom- 
plished in  two  generations. 

'S 

LOOKING  FORWARD 

In  the  preceding  pages  a  few  of  the  general 
principles  of  plant  development  have  been  out- 
lined, by  way  of  a  preliminary  sketch  of  Mr.  Bur- 
bank's  methods.  In  the  chapters  that  follow  these 
methods  will  be  illustrated  at  greater  length  and 
in  much  fuller  detail.  It  seemed  well,  however,  to 
prepare  the  reader  with  this  preliminary  outline 
for  the  detailed  studies  that  are  to  follow. 

In  the  immediately  succeeding  chapters,  we 
[40] 


THEORIES  OF  DEVELOPMENT 

shall  take  up  the  practical  aspects  of  Mr.  Bur- 
bank's  work,  in  effect  going  with  him  into  the 
fields  and  observing  the  carrying  out  of  the  prac- 
tical work  of  the  horticulturist.  It  will  be  con- 
venient first  to  examine  his  method  of  caring  for 
seeds  and  the  nature  and  development  of  seed- 
lings. Then  in  successive  chapters  we  shall  go 
with  him  into  the  orchard,  the  small-fruit  garden, 
the  vegetable  and  flower  gardens,  and  the  lawn 
and  dooryard,  gaming  characteristic  glimpses  of 
his  manifold  activities. 

It  is  obvious  that  with  the  space  at  command 
it  would  be  impossible  to  name  each  and  every  one 
of  the  plants  with  which  Mr.  Burbank  has  experi- 
mented effectively.  At  best  we  can  mention  only 
the  more  typical  or  the  more  spectacular  cases. 
But  I  would  again  remind  the  reader  that  a  very 
complete  exposition  of  his  entire  lifework  has 
been  given  by  Mr.  Burbank  himself  in  a  series  of 
volumes,  twelve  in  number,  illustrated  by  no  fewer 
that  twelve  hundred  and  sixty  beautiful  color 
plates.  To  this  work  the  reader  who  wishes  a 
more  extensive  presentation  of  the  work  of  plant 
development  as  carried  out  by  the  Santa  Eosa  ex- 
perimenter may  turn  with  full  confidence  and  with 
pleasurable  anticipations. 

Meantime  it  may  not  be  amiss  to  repeat  that  the 
present  book,  although  necessarily  condensed  in 
its  treatment,  endeavors  to  give  the  essentials  of 
Mr.  Burbank 's  methods  and  results,  and  that  the 
illustrations  of  Mr.  Burbank 's  work  here  pre- 
sented are  drawn  from  a  first-hand  study  of  his 

[41] 


LUTHER  BUKBANK 

activities  at  Santa  Eosa  and  Sebastopol,  and  the 
fullest  examination  of  the  original  manuscripts 
and  records  made  accessible  to  the  writer  in 
his  capacity  of  editor-in-chief  of  Mr.  Burbank's 
works. 


[42] 


PART   II 

WITH  LUTHEE  BURBANK  IN  ORCHARD, 
GARDEN,  FIELD,  AND  FOREST 


CHAPTER  III 
THE  CARE  OF  SEEDS  AND  SEEDLINGS 

IT  will  give  new  zest  to  your  work  in  the  gar- 
den to  feel  that  you  are  producing  new  varie- 
ties of  vegetables  or  fruit  or  flowers  not  only 
different  from  those  of  your  neighbors,  but  dif- 
ferent from  anything  that  ever  existed  before.  It 
would  have  seemed  paradoxical  a  few  years  ago 
to  suggest  such  creative  possibilities,  but  Mr.  Bur- 
bank  has  shown  the  way,  and  the  succeeding  chap- 
ters will  relate  his  methods  clearly  and  explicitly. 

In  broad  general  terms,  it  may  be  said  that  the 
Burbank  method  consists  of  (1)  the  selection  of 
desired  traits  and  their  accentuation  through  suc- 
cessive generations,  combined  with  (2)  artificial 
hybridization  through  which  variation  is  stimu- 
lated, and  through  which  different  racial  strains 
are  brought  together  to  produce  unique  combina- 
tions. 

The  precise  way  in  which  such  selective  breed- 
ing is  carried  out  will  be  specifically  detailed 
in  connection  with  our  studies  of  work  in  the 
orchard,  the  small-fruit  garden,  the  vegetable  gar- 
den, the  flower  garden,  and  on  the  lawn. 

But  as  preliminary  to  such  studies,  it  will  be 
well  to  learn  just  how  Mr.  Burbank  prepares  the 
soil  and  carries  out  the  tedious  but  necessary 

[45] 


LUTHER  BURBANK 

steps  of  seed  planting  and  the  nurture  of  seed- 
lings, which  are  substantially  the  same  for  all 
types  of  vegetables,  and  which  are  among  the  most 
essential  of  the  processes  of  practical  gardening. 

CHOICE   AND   CAEE   OF   SEEDS 

It  is  obvious  that  no  success  could  attend  the 
effort  at  plant  development  unless  seeds  are  prop- 
erly chosen  and  properly  cared  for.  After  experi- 
ments are  under  way,  you  will  of  course  gather 
seeds  from  your  own  plants,  but  at  the  beginning 
of  your  experiments  you  must  secure  seeds  from 
some  other  source.  Mr.  Burbank  especially  cau- 
tions you  to  procure  your  supplies  from  some 
reputable  seedsman,  so  that  you  may  have  fair 
assurance  that  you  are  making  a  good  beginning. 
It  is  obviously  foolish  to  begin  with  poor  varieties, 
when  you  might  with  equal  ease  have  good  varie- 
ties from  which  to  select.  Study  seed  catalogues, 
then,  and  decide  on  a  certain  number  of  species 
with  which  you  wish  to  experiment,  and  secure 
seeds  of  the  best  available  varieties  of  the  species. 

Mr.  Burbank  himself  regards  the  care  of  seeds 
as  among  the  very  most  important  phases  of  his 
work.  The  seeds  of  his  choicest  varieties  are  kept 
over  winter  in  boxes  in  a  room  of  his  own  dwell- 
ing, where  they  are  directly  under  his  eye,  and  the 
method  of  dealing  with  these  seeds  in  the  early 
springtime  is  one  to  which  he  has  given  a  vast 
deal  of  attention,  and  regarding  which  he  has  per- 
fected a  plan  that  insures  the  best  possible  results. 

[46] 


SEEDS  AND  SEEDLINGS 

Fortunately,  the  method  of  sprouting  seeds  is 
practically  the  same  for  the  most  diverse  kinds. 
Mr.  Burbank  has  seeds  sent  him  from  all  parts  of 
the  world.  He  applies  the  same  method  of  germi- 
nation to  them  all,  and  he  has  so  perfected  the 
method  that  he  confidently  expects  to  secure  at 
least  ninety-nine  seedlings  from  every  hundred 
seeds  of  whatever  kind. 

The  importance  of  being  able  to  germinate  seeds 
of  rare  exotics  with  some  such  degree  of  certainty 
is  obvious.  It  is  no  less  important  to  make  sure 
of  the  germination  of  seeds  produced  by  difficult 
hybridizing  experiments.  For  example,  Mr.  Bur- 
bank  worked  for  twenty-five  years  unsuccessfully 
in  attempting  to  hybridize  two  species  of  night- 
shade, and  finally  he  produced  a  single  berry. 
The  solicitude  with  which  he  guarded  the  seeds 
of  that  berry  may  well  be  imagined.  From  one 
of  those  seeds  sprang  the  plant  that  became  the 
progenitor  of  the  entire  race  of  sunberries. 

And  this  is  only  one  instance  of  many  in  which 
all  the  potentialities  of  a  new  race  of  fruits  or 
flowers  or  vegetables  were  represented  in  a  little 
cluster  of  seeds  that  by  the  slightest  mismanage- 
ment might  be  destroyed,  thus  bringing  to  naught 
a  long  series  of  experiments. 

Bearing  this  in  mind,  we  shall  not  wonder  that 
Mr.  Burbank  keeps  his  unique  collection  of  seeds 
constantly  under  his  own  eye,  or  that  he  person- 
ally supervises  the  planting  of  these  seeds  in  the 
early  springtime. 

[47] 


LUTHER  BURBANK 

PKEPABING   THE   SOIL 

It  is  Mr.  Burbank's  unvarying  custom  to  plant 
all  important  seeds  in  boxes  that  at  first  are  kept 
in  the  greenhouse,  so  that  the  seedlings  may  get 
an  early  start,  and  for  a  time  be  protected  from 
the  elements. 

For  many  years  he  has  used  boxes  of  a  uniform 
size  and  type,  and  such  boxes  he  considers  far 
better  than  pots  or  earthen  pans.  The  boxes  he 
uses  are  eighteen  inches  square,  outside  measure, 
and  four  and  one-half  inches  deep,  inside  measure. 
He  prefers  redwood  lumber,  but  where  this  cannot 
be  obtained  cypress  will  answer  nearly  as  well. 
Chestnut  wood  is  also  very  durable,  and  locust 
is  even  more  so.  Soft  pine  should  be  avoided. 

Two  opposite  sides  of  the  box  are  boards  three- 
quarters  or  seven-eighths  of  an  inch  thick,  the 
other  sides  are  a  little  less  than  half  an  inch  thick. 
The  bottom  of  the  box  is  made  of  lumber  about 
one-quarter  of  an  inch  thick,  two  or  more  spaces 
of  an  eighth  of  an  inch  being  left  for  drainage. 
Across  the  bottoms  are  nailed  three  strips  to  add 
rigidity  and  strength,  and  to  afford  better  ventila- 
tion and  drainage. 

It  is  well  to  dip  the  joints  in  linseed  oil  before 
they  are  nailed  together.  This  gives  durability 
and  tends  to  prevent  the  nails  from  rusting. 

Such  a  box  as  this,  if  sterilized  once  a  year  by 
being  placed  for  three  or  four  minutes  in  boiling 
water,  may  be  used  for  many  years. 

In  preparing  the  soil  to  fill  the  boxes,  Mr.  Bur- 
[48] 


SEEDS  AND  SEEDLINGS 

bank  uses  about  one-half  clean,  rather  coarse, 
sharp  sand,  and  about  forty  per  cent  of  good 
pasture  or  forest  soil,  preferably  that  containing 
more  or  less  leaf  mold.  To  this  it  is  desirable  to 
add  from  five  to  ten  per  cent  finely  powdered  moss 
or  peat.  These  ingredients  are  intimately  mixed, 
with  the  addition  of  about  one  or  two  per  cent  of 
fine-ground  bone  meal  or  superphosphate,  obtain- 
able from  any  dealer  in  gardener's  supplies. 

This  mixture  makes  a  soil  in  which  seeds  of 
almost  any  kind  of  plant  from  any  part  of  the 
world  will  germinate,  and  in  which  the  seedlings 
will  thrive  until  they  are  ready  for  transplanting. 

Mr.  Burbank  recommends  that  soil  of  this  kind, 
after  being  once  used,  shall  not  be  thrown  away, 
but  shall  be  retained  for  mixture  with  new  soil 
prepared  in  a  succeeding  season.  He  always 
keeps  a  little  of  the  old  soil  on  hand  for  this 
purpose. 

If  very  choice  seeds  are  to  be  grown,  the  soil, 
new  or  old,  is  sterilized  by  thorough  scalding  to 
destroy  bacterial  or  fungus  or  insect  pests. 

Before  filling  the  boxes  with  soil,  it  is  well  to 
scatter  coarse  gravel  over  the  bottom  to  a  depth 
of  from  one-quarter  to  a  half  inch.  Use  gravel 
that  will  just  pass  through  a  half -inch  mesh,  or 
a  little  smaller.  This  insures  perfect  drainage 
and  sufficient  aeration,  both  of  which  are  of  the 
utmost  importance. 

Then  fill  the  box  with  the  prepared  soil  to 
within  about  an  inch  of  the  top. 

When  cool  damp  weather  is  to  be  expected,  and 
[49] 


LUTHER  BURBANK 

slow  growth,  make  the  filling  somewhat  shallower 
to  prevent  drowning  or  "damping  off"  of  the 
seedlings.  For  spring  planting  make  the  earth  a 
little  deeper  to  prevent  too  sudden  drying  out, 
and  otherwise  to  regulate  the  amount  of  moisture. 

PLANTING   THE    SEEDS 

Having  filled  the  box  with  the  prepared  soil  to 
the  right  depth,  level  the  surface  of  the  soil  by 
pressing  it  down  with  a  flat  piece  of  board  until 
it  is  smooth  and  fairly  solid.  Then  sow  the  seeds 
quite  thickly  on  this  smooth  surface,  and  dust  a 
handful  of  the  prepared  soil  over  them.  In  the 
case  of  very  small  seeds,  a  mere  sprinkling  of  the 
soil  is  enough.  For  larger  seeds  sprinkle  the  soil 
to  a  depth  of  one-eighth  or  one-quarter  of  an  inch. 

A  very  common  mistake  is  to  cover  the  seeds 
too  deeply.  It  should  be  recalled  that  the  tender 
sprout  must  force  its  way  upward  against  the 
weight  of  soil  that  covers  it.  The  soil  covering 
should  be  sufficient  to  give  it  protection,  but  not 
enough  to  be  burdensome.  If  too  deeply  covered, 
tender  seedlings  may  not  be  able  to  force  their 
way  to  the  surface. 

When  seeds  are  planted  in  fields,  and  it  is  neces- 
sary to  give  them  protection  from  the  weather, 
Mr.  Burbank  entirely  covers  them  with  a  thin 
layer  of  earth  and  sprinkles  over  this  a  layer  of 
sawdust  which  will  serve  the  purpose  of  equaliz- 
ing the  temperature,  and  will  not  subject  the 
sprouting  plant  to  undue  weight.  Even  in  the 

[50] 


SEEDS  AXD  SEEDLINGS 

case  of  seeds  planted  in  boxes  the  sawdust  may  be 
used,  but  in  most  cases  powdered  moss  may  be 
employed  to  better  advantage. 

A  thin  layer  of  moss  sifted  over  the  seeds  acts 
as  a  non-conductive  blanket,  equalizing  the  tem- 
perature and  retaining  moisture. 

A  very  thin  layer  of  gravel  or  coarse  sand  may 
be  sprinkled  over  the  moss  to  hold  it  in  place. 
This  layer  of  gravel  not  only  prevents  the  young 
plants  from  being  washed  about,  but  also  serves 
as  a  barrier  against  the  spread  of  fungous 
growths  should  they  subsequently  attack  any  of 
the  seedlings. 

After  the  seeds  are  planted  and  covered  in  the 
way  just  described,  they  should  be  watered  not 
by  sprinkling  the  surface,  but  by  placing  the 
boxes  into  a  tub  containing  water  of  sufficient 
depth  to  rise  nearly  or  quite  to  the  surface  of  the 
soil.  Thus  in  a  few  minutes  the  water  saturates 
the  entire  contents  of  the  box  without  disturbing 
the  seed  or  packing  the  soil.  The  boxes  are  then 
removed  and  tilted  to  one  side  so  that  the  super- 
fluous water  can  drain  out. 

Mr.  Burbank  urges  that  every  detail  of  this 
process  of  soil  preparation  and  seed  planting  is 
of  vital  importance.  By  strict  attention  to  details, 
success  is  virtually  assured. 

CABE   OF   THE   SEEDLINGS 

Of  course  the  seed  boxes  should  be  kept  at  mod- 
erate temperature,  in  a  fairly  warm  room,  or  in 

[51] 


LUTHER  BURBANK 

the  greenhouse  until  the  season  is  far  enough  ad- 
vanced for  outdoor  transplanting. 

If  the  season  is  delayed,  it  will  be  well  to  trans- 
plant the  seedlings  from  the  original  box  into 
another  one  similarly  prepared,  in  order  that  they 
may  have  room  to  develop. 

In  the  case  of  small  plants  like  the  calceo- 
larias, lobelias,  begonias,  ferns,  and  the  like,  the 
little  plantlets  may  be  transplanted,  as  soon  as 
they  are  visible,  by  lifting  them  on  the  end  of  a 
moistened  quill,  pencil,  or  small  knife  blade,  and 
placing  them  in  a  box  that  has  been  previously 
moistened,  then  covering  them  with  glass  for  a 
few  days. 

If  the  seedlings  are  not  transplanted  at  this 
early  stage,  removal  should  not  be  deferred  be- 
yond the  time  when  the  little  plants  have  from 
two  to  four  leaves.  Transplanting  at  this  stage 
is  a  very  simple  process,  effected  with  quill  or 
knife  blade.  The  seedlings  should  be  placed  in 
straight  rows  in  new  boxes,  from  six  to  twelve 
rows  in  a  box,  according  to  the  size  of  the  plants. 

After  remaining  in  the  greenhouse  for  a  week 
or  two,  the  boxes  of  seedlings  are  removed  to  a 
sheltered  place  out  of  doors,  in  order  that  they 
may  become  hardened  through  exposure  to  sun- 
shine and  outdoor  air.  If  the  season  is  backward, 
it  may  be  desirable  to  transplant  the  seedlings 
a  second  time  into  other  boxes,  to  give  them  more 
room.  But  if  the  season  is  sufficiently  advanced 
they  may  be  transferred  directly  to  the  garden. 

Mr.  Burbank  especially  cautions  against  mak- 
[52] 


SEEDS  AND  SEEDLINGS 

ing  too  sudden  a  transfer  from  greenhouse  to 
field.  It  is  well  to  accustom  the  seedlings  to  out- 
of-door  conditions  by  placing  the  boxes  at  first 
in  propagating  beds,  surrounded  by  high  boards, 
and  covered  with  frames  made  of  laths  nailed  on 
narrow  strips  of  board  in  such  a  way  that  the 
spaces  between  the  laths  are  about  equal  to  the 
width  of  a  single  lath. 

These  frames  give  partial  protection  from  sun 
and  wind  and  prepare  the  seedlings  for  open-air 
conditions. 

In  making  the  final  transplantation,  it  is  well 
to  take  the  boxes  to  the  field  so  that  each  plant 
is  transferred  with  the  least  possible  exposure. 
In  California  tender  plants  best  withstand  mov- 
ing from  the  greenhouse  to  the  open  air  just  be- 
fore or  during  a  warm  rain,  the  atmospheric  con- 
ditions at  this  time  being  similar  to  those  of  a 
greenhouse. 

The  final  transplanting  is  done  with  a  trowel, 
taking  up  enough  dirt  to  include  all  the  roots. 
Mark  the  rows  with  a  guard  line,  and  make  a 
long  narrow  crevice  by  inserting  a  flat  spade  and 
moving  the  handle  back  and  forth  gently.  Be  sure 
that  the  crevice  is  deep  enough  to  take  in  the 
roots  of  the  plant  fully  extended.  Plant  the  seed- 
ling a  little  deeper  than  it  grew  in  the  box,  and 
draw  the  soil  about  it  and  pack  it  quite  firmly 
against  the  roots.  Use  the  common  garden  rake 
in  leveling  and  loosening  up  the  soil  along  each 
side  of  the  row  to  prevent  " baking,"  and  to  keep 
the  temperature  equable  and  the  soil  moist. 

[53] 


LUTHER  BURBANK 

The  tender  seedlings  may  be  destroyed  by  a 
cold  dry  wind,  or  by  too  much  moisture  and  too 
little  air.  They  should  be  protected  for  a  day  or 
two  if  a  dry  wind  comes  up,  and  the  soil  about 
them  should  not  be  soaked  with  water,  although 
kept  in  a  moist  condition. 

RUNNING  THE   GAUNTLET 

There  are  numerous  fungoid  and  insect  pests 
that  threaten  the  seedling  during  its  infancy. 
Little  patches  of  fungus  may  appear  in  a  box  of 
seedlings,  and  this  may  spread  rapidly  until  the 
entire  company  is  destroyed. 

A  sprinkling  of  sulphur  over  the  plants,  or  of 
coarse  dry  sand  or  gravel  about  their  roots,  may 
prevent  the  fungus  from  spreading.  It  will  be 
well  to  place  the  box  in  a  cold  dry  atmosphere  so 
that  the  excessive  moisture  is  evaporated.  The 
fungus  pests  are  most  likely  to  attack  the  seed- 
lings if  they  have  been  kept  in  too  close  and  damp 
an  atmosphere. 

After  the  plants  are  in  the  field  they  should 
quickly  develop  a  hardiness  that  makes  them  im- 
mune to  the  attacks  of  fungoid  pests.  Mr.  Bur- 
bank  has  all  along  made  a  very  particular  point 
of  the  development  of  hardy  races  of  plants.  He 
at  once  removes  and  destroys  any  seedlings  that 
show  susceptibility  to  the  fungus  or  bacterial 
pests.  In  this  way  he  develops  races  that  are 
immune,  and  he  never  finds  it  necessary  to  use 
germicidal  sprays  in  his  orchards  and  gardens. 

[54] 


SEEDS  AND  SEEDLINGS 

To  a  certain  extent  plants  may  be  developed 
that  are  resistant  also  to  the  attacks  of  insect 
pests.  But  it  is  necessary  to  guard  the  tender 
seedlings  against  the  attacks  of  these  enemies. 
One  should  be  on  the  lookout  from  the  outset  for 
the  various  cohorts  of  insects,  slugs,  cutworms, 
eel-worms,  crickets,  and  aphides  that  feast  on 
tender  tissues  of  seedlings. 

Slugs  may  sometimes  be  headed  off  by  sprin- 
kling lime,  red  pepper,  quassia,  or  tobacco  dust  in 
their  path. 

The  pests  known  as  the  thrips  and  the  aphides 
are  best  destroyed  by  fumigating  the  greenhouse 
once  or  twice  a  month  with  tobacco  smoke.  In 
general  a  careful  watch  should  be  kept  for  the 
pests,  and  the  seedlings  mechanically  guarded 
against  them  so  far  as  possible.  The  proper 
sterilization  of  the  soil  at  the  outset  will  save  a 
vast  deal  of  trouble  at  a  later  stage. 

The  description  just  given  outlines  the  method 
that  Mr.  Burbank  applies  to  the  seeds  that  come 
to  him  from  all  parts  of  the  world  and  to  those 
raised  on  his  own  grounds. 

The  rules  just  given  for  the  planting  of  seeds 
and  the  early  care  of  seedlings  apply  to  plants 
of  every  description.  Whatever  the  varieties  with 
which  you  intend  to  experiment, — flowers,  vege- 
tables, small  fruits,  orchard  fruits,  or  forest 
trees, — the  initial  steps  are  the  same. 


[55] 


CHAPTER  IV 
WITH  BURBANK  IN  THE  ORCHARD 

AjMOST  every  country  dooryard  has  one  or 
two  orchard  trees  in  some  odd  corner, — 
an  apple  or  pear  tree,  or  cherry  or  plum. 
For  the  most  part  these  trees  bear  indifferent 
fruit,  and  it  does  not  occur  to  their  owners  that 
they  could  be  improved.    Yet  in  point  of  fact  it 
would  be  an  easy  matter  to  graft  scions  or  buds 
of  good  stock  on  these  trees,  and  produce  fruits 
of    the    finest    varieties,    instead    of    inferior 
ones. 

You  may  have  a  hundred  or  more  different 
varieties  on  a  single  tree  if  you  like.  Mr.  Bur- 
bank  sometimes  has  a  thousand. 

Moreover,  it  would  be  quite  feasible  to  make 
the  old  tree  the  seat  of  experiments  in  the  devel- 
opment of  new  kinds  of  fruit — absolutely  new 
kinds,  such  as  no  one  ever  saw  before.  That  is 
what  Mr.  Burbank  would  do  with  the  tree.  He 
would  seek  its  co-operation  at  once ;  do  some  pol- 
lenizing  and  grafting;  and  pretty  soon  the  old, 
"worthless"  tree  would  be  the  most  interesting 
and  important  tree  in  that  part  of  the  world. 

The  ensuing  pages  will  tell  just  how  he  would 
go  about  it — and  how  you  may  imitate  his 
methods. 

[56] 


BURBANK  IN  THE  ORCHARD 

OEEATING   NEW    SPECIES 

Mr.  Bui-bank  early  discovered  that  by  hybridiz- 
ing different  species  of  plants  he  could  produce 
new  varieties — even  new  species. 

At  the  time  when  this  discovery  was  made  most 
botanists  and  horticulturists  supposed  that  a  cross 
between  two  species  would  be  infertile.  Mr.  Bur- 
bank  proved  that,  quite  to  the  contrary,  some 
hybrids  show  an  extraordinary  degree  of  fecund- 
ity. Everything  depends  upon  the  degree  of  re- 
lationship of  the  parent  forms.  Species  that  are 
too  widely  separated  do  not  interbreed.  Those 
that  are  a  little  less  widely  separated  may  pro- 
duce sterile  offspring, — mules.  Where  the  rela- 
tionship is  still  closer,  the  hybrid  offspring  may 
not  be  sterile,  and  yet  may  be  less  productive 
than  either  parent. 

But  where  the  degree  of  affinity  is  just  right, 
the  offspring  may  show  a  vigor  and  fecundity  far 
in  excess  of  that  of  either  parent. 

The  hybridizing  of  more  or  less  closely  related 
species  and  varieties  of  plants,  then,  constitutes 
a  fundamental  part  of  Mr.  Burbank's  procedure 
in  the  creation  of  new  forms.  He  has  hybridized 
about  two  hundred  different  species.  Among  the 
orchard  fruits  thus  crossed  are  the  plum  and  the 
apricot  (producing  the  wonderful  plumcot),  apple 
and  pear,  apple  and  quince,  quince  and  pear,  peach 
and  nectarine,  peach  and  almond,  and  orange  and 
lemon. 

Strange  and  interesting  forms  have  resulted 
[57] 


LUTHER  BURBANK 

from  some  of  these  crosses, — a  smooth-skinned 
peach  that  bears  an  edible  almond  seed  at  its 
heart,  to  name  a  single  example.  Crosses  between 
different  varieties  within  a  species  have  been 
made  by  thousands,  producing  hundreds  of  new 
varieties  of  plums,  prunes,  peaches,  apples,  pears, 
cherries,  and  quinces.  Stoneless  plums  and 
prunes ;  plums  that  look  like  apples  and  taste  like 
them;  gigantic  red-cheeked  pears;  cherries  for 
canning  that  leave  the  stone  on  the  tree  when  you 
pick  them;  colossal,  savory  quinces,  borne  on 
mere  bushes — these  are  some  of  the  results,  named 
almost  at  random.  Hybridizing  experiments  that 
hold  out  such  possibilities  are  worth  trying.  We 
shall  see  how  to  go  about  them  in  a  moment. 

Another  fundamental  method,  supplementing 
the  method  of  hybridization,  is  that  of  selection 
among  varying  individuals  of  the  same  species 
or  variety.  No  two  individuals  are  just  alike, 
from  which  it  follows  that  in  a  given  company  of 
plants  of  the  same  kind  there  are  various  grada- 
tions as  to  size  and  shape  of  leaf,  form  and  color 
of  flower,  or  flavor  of  fruit ;  and,  as  regards  each 
varying  quality,  there  must  obviously  be  one  in- 
dividual, if  you  will  carefully  search  it  out,  that 
exhibits  this  quality  most  markedly.  Or  there 
may  be  an  individual  that  shows  just  a  trace  of 
a  new  quality — say  a  unique  flavor  or  color. 

This  is  the  individual  to  select  for  further 
breeding  experiments,  in  expectation  of  accentu- 
ating the  quality  in  question. 

For  instance,  Mr.  Burbank  found  a  cherry  that 
[58] 


BURBANK  IN  THE  ORCHARD 

tended  to  fruit  early:  its  descendant  is  the  Early 
Burbank,  which  ripens  three  weeks  before  any 
other  cherry.  He  found  a  hybrid  prune  that  was 
a  trifle  sweeter  than  its  fellows :  its  descendant  is 
the  Burbank  sugar  prune,  with  its  twenty-three 
per  cent  sugar  content.  He  found  a  quince  with 
slightly  modified  texture  and  flavor:  its  descend- 
ant is  the  pineapple  quince,  gigantic  in  size,  good 
to  eat  raw  like  an  apple,  and  with  the  flavor  of 
a  pineapple.  Any  quality  that  can  be  detected  at 
all  can  almost  surely  be  accentuated  by  selective 
breeding. 

SEEDS   AND   SEEDLINGS 

In  experimenting  with  a  plant,  Mr.  Burbank 
has,  of  course,  a  clear  idea  of  the  modification  he 
wishes  to  produce.  As  a  rule,  a  number  of  quali- 
ties— often  a  dozen  or  more — are  under  considera- 
tion at  the  same  time. 

If  the  fruit  is  a  cherry,  for  example,  it  will 
perhaps  be  desirable  to  enlarge  the  fruit,  make  it 
sweeter,  redder,  and  juicier;  improve  its  keeping 
quality;  decrease  the  size  of  the  stone,  and 
shorten  the  stem;  while  at  the  same  time  making 
the  tree  a  hardy,  regular,  and  prolific  bearer,  with 
the  fixed  habit  of  ripening  its  fruit  very  early  in 
the  season. 

To  get  such  a  combination,  the  right  heredities 
must  be  blended,  as  a  matter  of  course.  But  there 
will  be  extraordinary  diversities  in  the  same  fra- 
ternity; and  the  chance  of  securing  a  plant  that 
shows  any  given  combination  of  qualities  in  super- 

[59] 


LUTHER  BURBANK 

lative  degree  increases  in  direct  proportion  with 
the  number  of  seedlings  from  which  selection  can 
be  made. 

Hence  one  of  Mr.  Burbank 's  hobbies  is  the  pro- 
duction of  seedlings  in  great  quantity.  This  is 
not  so  essential  in  hybrid  seedlings  in  the  first 
generation,  but  it  is  highly  important  in  the  second 
generation,  because  then  the  plants  begin  to  show 
a  very  wide  range  of  variation — f  or  reasons  that 
we  shall  examine  in  another  connection. 

So  Mr.  Burbank  saves  all  the  seeds  of  a  plant 
that  attracts  his  attention,  and  sows  them  in  a 
carefully  prepared  soil  in  greenhouse  boxes.  De- 
tails as  to  his  method  have  already  been  given. 
We  may  add  that  the  same  method  is  used  for 
seeds  of  practically  every  variety, — rare  exotics 
of  many  kinds  and  the  commonest  garden  plant; 
seed  of  the  spineless  cactus  or  that  of  orchard 
fruit.  Whatever  the  variety,  Mr.  Burbank  nur- 
tures and  transplants  the  tiny  seedlings,  giving 
each  one  of  them  a  chance  to  show  its  quality  in 
open  competition. 

RUNNING   THE   GAUNTLET 

The  tiny  seedlings  of  the  plum  or  the  cherry  or 
apple  or  pear  or  quince  are  transplanted  into  a 
field  pretty  close  together,  for  economy  of  space, 
and  are  carefully  weeded  and  cultivated  until  they 
attain  an  average  growth  of  about  one  foot. 

Then  Mr.  Burbank  subjects  them  to  a  rigid  in- 
spection. He  passes  along  the  row,  and  gives  a 

[60] 


BURBANK  IN  THE  ORCHARD 

quick  but  searching  glance  at  each  successive 
seedling.  He  knows  precisely  what  he  is  looking 
for,  and  his  eye  detects  niceties  of  variation  that 
would  be  discerned  by  no  one  else. 

Mr.  Burbank  is  able  thus  to  pass  under  review, 
for  appraisal,  five  thousand,  ten  thousand,  even 
twenty  thousand  seedlings  in  an  hour.  This  ca- 
pacity for  almost  occult  divination  of  the  qualities 
of  the  seedling  enables  him  to  make  thousands  of 
series  of  experiments  simultaneously,  and  to  test 
millions  of  plants  on  experiment  farms  that  have 
an  aggregate  surface  of  only  twenty-two  acres. 
He  is  always  carrying  forward  at  least  three  thou- 
sand series  of  experiments.  All  in  all,  he  has  car- 
ried out  more  than  one  hundred  thousand  such 
series  of  experiments,  involving  almost  as  many 
varieties  of  plants  (for  he  seldom  repeats  an  ex- 
periment), and  more  than  three  thousand  distinct 
species. 

It  will  be  understood,  of  course,  that  the  experi- 
ment is  not  finished  when  the  seedlings  are  se- 
lected. It  is  really  only  begun.  The  selected  seed- 
ling must  be  grafted,  and  allowed  in  due  course  to 
bear  fruit.  Then,  and  not  before,  can  its  quality 
be  finally  and  positively  known. 

Visitors  who  have  seen  Mr.  Burbank  making 
such  a  test  as  that  just  suggested  have  sometimes 
questioned  whether  it  could  possibly  be  a  really 
accurate  one. 

The  results  achieved  should  fairly  enough  an- 
swer the  question,  but  the  matter  has  been  put 
to  an  even  more  decisive  test.  On  one  occasion, 

[61] 


LUTHER  BURBANK 

Mr.  Burbank  was  selecting  among  thousands  of 
plum  seedlings,  directing  his  assistants  to  uproot 
them  and  deposit  them  in  three  piles, — a  very 
small  pile  for  those  that  he  deemed  excellent,  a 
medium-sized  pile  for  the  fairly  good  ones,  and 
a  large  pile  for  those  that  were  regarded  as  worth- 
less. 

An  amateur  horticulturist  who  watched  him  de- 
clared that  he  was  making  the  selection  much  too 
rapidly,  and  that  he  could  not  possibly  forecast 
the  possibilities  of  the  seedling  with  certainty. 
Mr.  Burbank  suggested  that  he  put  the  matter  to 
a  test. 

Accordingly  a  bunch  of  seedlings  was  taken 
from  each  pile,  and  grafted  on  three  plum  trees 
of  similar  size  and  character  that  stood  side  by 
side. 

Of  course  it  was  necessary  to  wait  two  or  three 
years  to  learn  the  result.  But  when  the  grafted 
scions  were  old  enough  to  bear  fruit,  the  accuracy 
of  Mr.  Burbank 's  prevision  was  fully  proved. 
The  scions  from  the  rejected  lot  bore  no  fruit  of 
value.  Those  from  the  medium  lot  bore  some 
fairly  good  fruit,  but  not  one  that  produced  a 
variety  of  exceptional  value. 

Meantime  the  tree  bearing  the  scions  that  were 
originally  selected  as  "best"  bore  such  a  pro- 
fusion of  excellent  fruit,  of  twenty-three  different 
new  varieties,  that  the  amateur  who  had  sug- 
gested the  experiment  named  it  the  Klondike,  de- 
claring that  he  had  never  before  seen  so  much 
good  fruit  on  a  single  tree. 

[62] 


BURBANK  IN  THE  ORCHARD 

HOW   TO   SELECT   SEEDLINGS 

This  capacity  to  judge  the  possibilities  of  a 
future  tree  by  merely  glancing  at  the  seedling  is 
doubtless  in  part  a  matter  of  intuition. 

It  has  been  said  of  Mr.  Burbank,  perhaps  with- 
out much  exaggeration,  that  he  has  the  keenest 
senses  of  any  man  in  the  world.  But  of  course  a 
profound  knowledge,  based  on  a  lifetime  of  study, 
supplements  and  checks  direct  observation,  and 
something  of  this  knowledge  can  be  conveyed  to 
others. 

Doubtless  no  one  else  can  hope  to  select  seed- 
lings with  quite  the  certainty  of  the  master,  yet 
everyone  can  learn  at  least  a  few  general  char- 
acteristics that  should  be  looked  for  in  the  seed- 
ling of  a  future  fruit  tree. 

Mr.  Burbank  tells  us  that  the  desirable  qualities 
include  relative  thickness  and  sturdiness  of  stock 
and  branches,  round  "fat"  buds,  and  large  thick 
leaves  of  deep  rich  color.  Vigor  of  growth  is  also 
important,  this  being  an  inherent  trait  that  is 
manifested  by  the  seedling  from  the  moment  that 
it  breaks  through  the  soil.  A  tendency  to  upright 
growth  is  also  desirable.  A  seedling  that  shows 
these  qualities,  and  that  has  the  general  appear- 
ance of  health  and  entire  freedom  from  fungous 
growths,  may  safely  be  looked  to  as  a  future  pro- 
ducer of  fruit  of  good  quality. 

On  the  other  hand,  a  seedling  that  lacks  vigor, 
is  of  slender  stock  and; branch,  with  thin  buds  and 
leaves  of  poor  shape  or  faded  color,  should  be 

[63] 


LUTHER  BURBANK 

rejected.  And  in  particular,  any  seedling  that  is 
attacked  by  mildew  or  other  fungous  growths, 
whatever  its  other  qualities,  should  be  at  once  up- 
rooted. Immunity  to  disease  is  a  sine  qua  non. 
The  quality  that  gives  immunity  is  inherent  in 
the  germ-plasm  of  the  individual,  and  a  susceptible 
seedling  will  make  a  susceptible  tree. 

Mr.  Burbank's  trees  do  not  need  to  be  sprayed 
to  protect  them  against  bacterial  and  fungous  dis- 
eases, because  they  are  raised  from  immune  stock. 

In  developing  an  orchard  you  will  do  well  to 
follow  the  same  rule  rigidly,  even  though  it  leads 
you  to  destroy  seedlings  that  otherwise  appeared 
to  be  the  best  in  an  entire  lot. 

HUKRYING  THE   SEEDLINGS  BY  GRAFTING 

Of  course  the  seedlings  that  are  selected  for 
preservation  might  be  transplanted  and  left  to 
develop  on  their  own  roots. 

But  this  would  be  much  too  slow  a  process  to 
meet  the  needs  of  Mr.  Burbank's  experiments. 
He  knows  that  as  a  rule  he  must  carry  the  experi- 
ment through  several  generations  before  he  has 
developed  the  choice  new  variety  of  fruit  that  he 
has  in  mind. 

That  is  to  say,  he  must  await  the  flowering  of 
his  seedlings;  cross-fertilize  them;  save  the  seeds 
of  their  fruit,  plant  them,  and  raise  another  crop 
of  seedlings ;  which  in  turn  will  be  submitted  to 
the  same  process  of  selection,  grafting,  and  cross- 
fertilization.  The  object  is  to  breed  into  the  com- 

[64] 


MR.    BTJRBANK    INSPECTING    CROSS-BRED    TOMATO    SEEDLINGS 

The  specimens  depicted  were  altogether  extraordinary,  in  that  the 
cotyledons  shown  when  they  first  issued  from  the  ground  were  not 
smooth,  as  is  almost  invariable  with  every  species  of  plants,  but  deeply 
serrated.  In  all  Mr.  Bin-bank's  experiments,  involving  inspection  of 
millions  on  millions  of  seedlings,  he  has  never  observed  this  phenomenon 
before.  These  specimens  appeared  in  the  season  of  1914. 


BURBANK  IN  THE  ORCHARD 

plex  hybrid  the  diverse  traits  of  different  species. 
Of  course  only  two  species  can  be  blended 
in  a  single  cross,  so  repeated  crossings  will  be 
necessary. 

Obviously,  then,  it  is  desirable  to  shorten  as 
much  as  possible  the  interval  between  generations. 
And  Mr.  Burbank  has  learned  that  the  way  in 
which  this  may  best  be  accomplished  is  by  cutting 
the  seedling  from  its  own  roots,  and  grafting  it  as 
a  scion  on  the  branch  of  a  mature  tree. 

He  has  discovered  that  if  the  graft  is  placed 
on  the  trunk  of  a  tree  or  on  a  large  branch,  it  will 
develop  less  rapidly  than  if  placed  on  a  twig  near 
the  end  of  a  branch.  So  he  grafts  his  seedlings 
in  this  way  when  they  are  very  small,  putting 
them  on  branches  that  are  usually  not  more  than 
half  an  inch  in  diameter.  Thus  placed,  the  scions 
usually  bear  fruit  in  the  second  year  (exception- 
ally, even  in  the  first),  whereas  if  they  had  been 
left  to  grow  on  their  own  roots  they  might  not 
have  borne  until  the  fifth  or  sixth  year. 

Thus  an  experiment  may  be  carried  through 
four  or  five  generations  in  the  time  that  would 
otherwise  be  required  for  two  generations.  By 
the  adoption  of  such  time-saving  methods,  Mr. 
Burbank  has  been  able  to  crowd  the  work  of  sev- 
eral human  generations  into  a  single  lifetime. 

There  are  several  methods  of  grafting,  but  the 
essential  principle  with  all  of  them  is  merely  that 
the  inner  or  living  layer  of  the  bark — called  the 
cambium  layer — of  the  stock  and  scion  shall  be 
brought  in  contact,  not  necessarily  throughout  its 

[65] 


LUTHER  BURBANK 

extent,  but  at  least  in  one  place.  If  a  scion  is  to 
be  grafted  on  a  branch  of  its  own  size,  or  not  very 
much  larger,  each  is  cut  across  obliquely,  and  each 
is  slit  or  notched,  so  that  when  pressed  together 
they  interlock,  the  scion  thus  being  held  pretty 
firmly.  Such  a  graft  is  called  a  "whip"  graft  or 
"splice"  graft. 

A  scion  may  be  engrafted  on  the  trunk  of  a 
sapling  by  bending  the  sapling  and  making  an 
oblique  incision  with  a  knife,  into  which  the 
wedge-shaped  scion  is  inserted,  care  being  taken, 
of  course,  that  the  living  tissues  come  in  contact. 
This  is  called  a  "side"  graft.  The  same  method 
may  be  employed  to  graft  a  scion  on  the  root  of 
a  tree. 

Where  the  graft  is  planted  on  a  larger  limb, 
the  method  of  "cleft"  grafting  is  employed.  This 
consists  of  sawing  off  the  branch  of  the  stock, 
and  splitting  it  with  a  knife  or  wedge  at  the  end. 
The  base  of  the  scion  is  cut  into  a  wedge  shape, 
and  this  is  thrust  into  the  cleft  in  such  a  way 
that  the  inner  bark  of  the  scion  comes  in  con- 
tact with  that  of  the  stock.  A  scion  may  be  in- 
serted on  either  side  of  the  stock,  or  in  the  case 
of  a  large  branch  four  or  more  scions  may  be 
placed  on  the  same  branch. 

The  process  of  grafting  is  completed  by  cover- 
ing the  exposed  surfaces  with  grafting-wax,  and 
wrapping  a  cloth  about  the  branch  for  further 
protection  during  the  time  of  healing.  Mr.  Bur- 
bank's  formula  for  grafting- wax  is  as  follows: 

"Eight  pounds  of  resin  and  one  pound  of  bees- 
[66] 


BURBANK  IN  THE  ORCHARD 

wax  or  paraffin  (either  will  do  if  no  acid  or  alkali 
is  present,  though  beeswax  is  generally  preferred) 
are  mixed  with  one  and  one-half  pounds  of  raw 
linseed  oil.  Boiled  oil  should  be  avoided,  as  it 
often  contains  chemicals  injurious  to  plant  life. 
If  the  wax  is  to  be  used  in  cold  weather,  it  is 
better  to  use  only  seven  and  one-half  pounds  of 
resin  and  a  half-pound  of  beeswax  in  the  mixture, 
thus  giving  a  slightly  thinner  consistency." 

The  ingredients  are  slowly  heated  together 
until  melted  and  thoroughly  combined.  When 
partly  cool,  the  composition  is  poured  into  pressed 
tin  pans,  from  which  the  cakes  may  be  removed 
when  needed  by  turning  the  pan  upside  down  and 
pouring  boiling  water  over  it  for  a  few  seconds. 
For  use,  the  wax  is  heated,  preferably  in  a  double 
heater,  the  outer  one  containing  water,  to  prevent 
overheating.  It  is  applied  with  a  small  paint- 
brush, first  around  the  thick  bark  of  the  stock, 
and  later,  as  the  wax  on  the  brush  cools,  on  and 
about  the  cut  surfaces  and  open  joints. 

THE   PEOCESS   OF   BUDDING 

When  Mr.  Burbank  has  to  deal  with  a  very 
rare  seedling,  or  one  that  he  wishes  to  multiply 
rapidly,  he  uses  the  modified  form  of  grafting 
known  as  budding. 

The  process  consists  in  slicing  off  a  well-ripened 
bud,  including  a  piece  of  bark  about  an  inch  and 
a  half  long,  the  incision  being  just  deep  enough 
to  include  the  cambium  layer  and  a  small  portion 

[67] 


LUTHER  BURBANK 

of  wood.  A  T-shaped  incision  is  made  in  the 
bark  of  the  tree  that  is  to  serve  as  host ;  the  upper 
corners  of  the  vertical  slit  are  gently  lifted  with 
a  knife  and  turned  back  to  reveal  the  cambium 
layer ;  and  the  bud  is  slipped  into  the  little  pocket 
thus  formed,  and  the  flaps  of  bark  are  brought 
over  it  and  securely  tied.  No  wax  is  required. 
The  binding  cord  must  be  removed  in  from  ten 
to  fourteen  days,  in  order  not  to  constrict  the 
branch. 

Ordinary  grafting,  as  described  above,  may 
best  be  performed  rather  early  in  the  spring,  or 
just  as  the  buds  are  starting.  But  budding  is 
usually  done  in  June,  July,  or  August,  while  the 
trees  are  in  full  leaf  and  vigorous  growth.  Per- 
haps the  best  time  is  just  before  the  end  of  the 
most  rapid-growing  season  in  the  early  summer. 
If  transplanted  late  in  summer,  the  bud  usually 
remains  dormant  until  the  following  spring. 

If  budding  is  done  in  June,  the  branch  should 
be  broken  over  a  short  distance  above  the  bud, 
but  not  at  first  wholly  removed,  to  keep  up  a 
partial  circulation.  The  bud  may  then  start 
growing  almost  immediately.  These  are  called 
June  buds  by  nurserymen. 

A  branch  from  three  to  six  feet  in  length  may 
grow  from  a  bud  in  a  single  season. 

If  you  have  young  seedlings  with  vigorous 
roots,  they  may  be  grafted  or  budded  with  choice 
varieties,  and  in  many  cases  a  better  tree  will 
be  secured  than  if  it  grew  on  its  own  roots.  It 
will  be  understood,  however,  that  scions  must  be 

[68] 


BURBANK  IN  THE  ORCHARD 

grafted  on  trees  of  kindred  species.  You  cannot 
graft  a  stone  fruit,  for  example,  on  a  seed  fruit, 
or  vice  versa.  But  a  cultivated  apple  may  thrive 
when  grafted  on  roots  of  the  wild  crab  apple. 
Pear  scions  do  well  on  wild  or  inferior  varieties 
of  pears.  Cultivated  varieties  of  plums  may  be 
grafted  on  hardy  and  vigorous  wild  plums. 
Apricot  scions  thrive  on  seedling  plum  or  peach 
stock. 

One  of  Mr.  Burbank's  striking  feats  in  his  early 
experience  in  California,  while  he  was  carrying  on 
the  business  of  a  nurseryman,  was  to  establish  an 
orchard  of  twenty  thousand  prunes  in  a  single 
season  by  raising  almonds  from  seed  (sprouting 
them  between  layers  of  gunnysack  covered  with 
moist  sand),  and  grafting  prune  scions  on  them 
as  soon  as  they  were  large  enough. 

Mr.  Burbank  habitually  tests  scores  or  even 
hundreds  of  new  varieties  on  a  single  tree.  On 
his  Gold  Ridge  Farm  at  Sebastopol  there  are 
single  acres  on  which  ripen  several  thousand  dis- 
tinct varieties  of  hybrid  seedling  plums  that,  if 
tested  each  on  a  separate  tree,  would  require,  it 
is  estimated,  something  like  seven  hundred  acres 
of  land. 

It  is  obvious,  then,  that  if  you  have  on  your 
grounds  an  apple  tree  or  two,  a  plum,  a  pear, 
and  a  cherry,  even  if  they  are  all  of  inferior  varie- 
ties, you  may  quickly  establish  colonies  of  all  the 
common  orchard  fruits,  in  the  choicest  varieties, 
by  grafting  or  budding  with  scions  that  may  be 
secured  from  any  good  nursery. 

[69] 


LUTHER  BURBANK 

Under  the  circumstances,  it  is  your  own  fault 
if  your  trees  do  not  produce  good  fruit. 

SEEKING   NEW  VAEIETIES 

An  added  advantage  that  Mr.  Burbank  gains 
by  having  many  varieties  of  an  orchard  fruit 
growing  on  a  single  tree  is  that  the  process  of 
hybridizing,  through  which,  as  we  have  seen,  new 
varieties  are  developed,  is  thus  facilitated.  This 
process  consists  primarily  in  fertilizing  the  flower 
of  one  variety  with  pollen  from  another.  The 
process  is  a  simple  one,  particularly  in  the  case 
of  the  orchard  fruits.  Its  results  are  sometimes 
very  remarkable,  but  of  course  they  are  not  im- 
mediately manifest. 

If  you  examine  the  flower  of  apple  or  plum  or 
cherry,  you  will  see  that  it  bears  a  cluster  of 
stamens  grouped  about  the  central  pistil.  Each 
stamen  has  at  its  end  an  anther  that  when 
mature  bursts  open  and  reveals  a  quantity  of 
pollen. 

Under  natural  conditions  the  pollen  is  trans- 
ferred from  one  flower  to  another  through  the 
agency  of  bees,  and  natural  hybrids  are  not  in- 
frequently thus  produced. 

All  that  is  necessary  to  produce  cross-fertiliza- 
tion (where  the  plants  are  closely  related)  is  to 
transfer  pollen  from  one  flower  to  the  pistil  of 
another.  It  will  be  well  to  remove  the  stamens 
from  the  flower  to  be  fertilized,  with  a  pair  of 
small  forceps,  before  they  have  ripened,  thus  pre- 

[70] 


BURBANK  IN  THE  ORCHARD 

venting  self-fertilization.  Then  the  pollen  from 
another  flower  may  be  dusted  on  a  watch  crystal, 
and  thence  transferred  with  the  finger  tip  or  with 
a  small  eamel's-hair  brush  to  the  pistil  of  the 
flower  to  be  fertilized. 

Cover  the  pistil  thoroughly  with  pollen,  and 
there  will  be  little  danger  that  any  foreign  pollen 
may  subsequently  find  lodgment;  particularly  if 
the  petals  of  the  flower  are  cut  away,  so  that  it 
will  no  longer  attract  bees. 

Mr.  Burbank  sometimes  saves  time,  in  the  case 
of  orchard  fruits,  by  operating  on  a  blossom  just 
before  it  opens,  cutting  it  across  with  a  sharp 
knife  in  such  a  way  as  to  remove  the  pollen- 
bearing  anthers  at  the  ends  of  the  stamens,  care 
being  taken  not  to  injure  the  pistil  at  the  center  of 
the  flower.  Pollenation  is  then  effected  (after  the 
pistil  ripens)  in  the  way  just  described. 

In  operating  on  a  large  scale,  Mr.  Burbank  does 
not  find  it  expedient  to  cover  the  flowers  with 
paper  bags,  nor  does  he  think  it  necessary  to  do 
so.  But  the  amateur  who  has  plenty  of  time  at 
his  disposal  may  give  the  flowers  this  added  pro- 
tection if  he  so  desires.  The  object  is  simply  to 
make  sure  that  the  bees  do  not  accidentally  trans- 
fer pollen  to  the  pistil,  and  thus  perhaps  compli- 
cate the  experiment. 

Such  cross-pollenation,  through  which  the 
strains  of  various  races  or  species  of  orchard 
fruits  are  blended,  constitutes  a  very  essential 
part  of  Mr.  Burbank 's  work.  In  this  way  he  has 
brought  together  the  racial  strains  of  plums  from 

[71], 


LUTHER  BURBANK 

Japan  and  Europe,  and  blended  them  with  those 
of  American  plums,  producing  extraordinary  new 
varieties;  and  the  strains  of  apples,  pears, 
peaches,  quinces,  and  cherries,  from  the  most 
widely  separated  geographical  regions,  have  been 
similarly  blended. 

CEEATING   NEW  FRUITS 

One  time  when  Mr.  Burbank  was  a  young  man 
he  was  browsing  in  a  San  Francisco  library,  and 
came  across  an  account,  written  by  a  wandering 
sailor,  of  a  remarkable  red  plum  found  in  Japan, 
and  spoken  of  by  the  sailor  as  the  "  Blood  Plum 
of  Satsuma."  Mr.  Burbank  at  once  sent  to  Japan 
for  this  plum,  among  others,  and  he  ultimately 
secured  a  specimen,  which  became  the  progenitor 
of  all  the  different  varieties  of  red-fleshed  plums 
that  are  now  to  be  found  anywhere  in  America. 
Some  of  the  other  Japanese  plums, — and  the 
Chinese  plum  as  well, — when  blended  with  Amer- 
ican and  European  plums,  were  equally  notable 
as  producers  of  new  and  remarkable  varieties. 

Of  the  sixty  odd  new  varieties  of  plums  and 
prunes  that  Mr.  Burbank  has  introduced,  no  fewer 
than  thirty-eight  bear  strains  of  the  Asiatic 
plums,  fourteen  were  developed  from  American 
stock,  and  thirteen  from  European  species.  But 
the  various  strains  have  been  intimately  blended. 
A  single  complex  hybrid  may  reveal  the  brilliant 
color  and  delicious  fragrance  of  the  Chinese  plum, 
the  red  fruit  pulp  and  large  size  of  the  Japanese, 

[72] 


BURBANK  IN  THE  ORCHARD 

the  hardiness  and  fine  flavor  of  an  American  wild 
plum,  and  the  sweeetness  of  a  European  pro- 
genitor. 

By  hundreds  of  carloads,  in  the  aggregate,  the 
various  Burbank  hybrid  plums  are  sent  to  the 
eastern  markets  each  season. 

One  of  Mr.  Burbank 's  most  celebrated  experi- 
ments was  that  in  which  he  hybridized  the  plum 
and  the  apricot,  producing  a  wonderful  new  fruit, 
the  plumcot.  The  hybridization  was  effected  with 
difficulty,  because  the  two  strains  were  so  dis- 
tantly related,  but  it  was  finally  accomplished, 
and  now  there  are  many  varieties  of  plumcots  in 
the  orchards  at  Sebastopol. 

Among  the  new  varieties  that  Mr.  Burbank  has 
developed  by  this  method,  none  perhaps  has  ex- 
cited more  general  interest  than  the  stoneless 
plum.  A  fruit  that  exteriorly  looks  like  any  other 
plum,  yet  which  offers  no  resistance  to  the  teeth 
when  you  bite  right  through  it,  is  obviously  some- 
thing quite  out  of  the  ordinary. 

The  stoneless  plum  was  developed  by  a  long 
series  of  hybridizing  experiments  in  which  the 
original  progenitor  was  a  small  "freak"  plum  of 
acrid  and  inedible  quality,  that  through  some 
abnormality  was  partially  stoneless.  This  little 
plum  grew  wild  in  France,  and  was  not  consid- 
ered of  any  value.  Mr.  Burbank  secured  a  speci- 
men, however,  and  hybridized  its  blossoms  with 
various  cultivated  plums. 

The  problem  was,  to  breed  into  the  hybrid  the 
qualities  of  the  commercial  plum,  while  retaining 

[73] 


LUTHER  BURBANK 

and  accentuating  the  tendency  to  stonelessness. 
This  proved  exceedingly  difficult.  But  by  per- 
severing through  a  long  series  of  generations,  sav- 
ing always  for  seed  purposes  the  seedlings  that 
showed  most  improvement,  and  grafting  them  in 
the  way  above  described  to  hasten  their  develop- 
ment, Mr.  Burbank  finally  succeeded  in  producing 
not  merely  one  variety,  but  several  varieties  of 
plums  and  prunes  of  large  size  and  of  excellent 
quality  that  are  almost  absolutely  stoneless,  re- 
taining at  most  a  tiny  fragment  of  shell  at  one 
end  of  the  seed.  Some  varieties  have  shown  a 
marked  tendency  to  eliminate  the  seed  itself  as 
well. 

The  contrast  between  the  cranberry-sized  par- 
tially stoneless  French  plum,  with  its  inedible 
flesh,  and  the  mammoth  stoneless  plum  of  delicious 
quality  that  is  descended  from  it  is  very  striking. 

SUGGESTIONS  FOB   THE  AMATEUR 

The  development  of  such  a  fruit  required  years 
of  time  and  an  almost  inexhaustible  supply  of 
energy  and  patience.  But  the  principles  involved, 
from  first  to  last,  were  merely  those  that  have 
been  outlined  above.  Hybridization  and  selection 
— these  are  the  methods  of  the  fruit  developer  as 
perfected  by  Mr.  Burbank.  Intelligently  inter- 
preted and  systematically  followed  up,  they  make 
possible  almost  any  desired  transformation  in 
plant  life. 

jLet  this  not  be  misunderstood,  Selection  of 
[74] 


BURBANK  IN  THE  ORCHARD 

material  and  the  right  blending  of  the  material 
are  the  essential  methods  of  the  plant  developer. 
But  the  creative  work  of  a  master  painter  might 
be  described  in  the  same  terms.  In  each  case, 
everything  depends  upon  how  the  materials  are 
used. 

The  "  wizardry "  that  one  hears  ascribed — and 
very  justly  ascribed — to  Mr.  Burbank  has  for  ac- 
cessories the  methods  of  hybridization  and  selec- 
tion, but  these  are  applied  with  (1)  the  creative 
genius  that  can  conceive  the  ideal  of  a  specific 
plant  development,  plus  (2)  prevision  in  selecting 
forms  to  hybridize,  plus  (3)  a  sixth-sense  intui- 
tion in  noting  nice  shades  of  variation,  plus  (4) 
indefatigable  energy  .in  following  up  an  experi- 
ment, and  inexhaustible  patience  in  the  face  of 
temporary  bafflement. 

In  a  word,  certain  mechanical  methods  plus 
genius  account  for  the  work  of  Luther  Burbank. 
But  the  mechanical  methods,  after  all,  are  essen- 
tials. You  cannot  become  a  master  painter  merely 
by  inspecting  the  palette  of  a  great  artist;  but 
you  can  never  hope  to  paint  at  all  if  you  do  not 
learn  the  rudiments  of  pigment-mixing.  Sim- 
ilarly you  will  not  necessarily  become  a  Burbank 
because  you  learn  to  hybridize  and  select,  but  you 
must  learn  these  things  if  you  are  to  attempt  plant 
development  at  all. 

Moreover,  here,  as  in  many  other  fields,  you 
may  repeat  an  experiment  that  you  might  not  have 
preconceived.  Many  an  amateur  can  make  a 
fairly  presentable  copy  of  a  masterpiece. 

[75] 


LUTHER  BURBANK 

Each  of  Mr.  Burbank's  great  plant  develop- 
ments is  a  masterpiece  of  experimental  applica- 
tion. Yet  many  of  these  developments  might  be 
duplicated,  now  that  the  methods  are  known,  by 
any  intelligent  amateur  who  will  give  attention 
to  details. 

It  is  possible  for  you  to  apply  the  methods  on 
a  small  scale  even  though  you  have  but  a  single 
fruit  tree.  Indeed,  with  a  ten-foot  plot  of  ground 
for  the  raising  of  seedlings,  and  a  single  tree  on 
which  to  graft,  you  may  experiment  to  your 
heart's  content. 

And  although  you  cannot  expect  to  produce 
plumcots  or  stoneless  plums  or  superlative  varie- 
ties of  peaches  or  apples  or  pears  or  cherries 
without  expenditure  of  effort,  you  may  at  least 
hope  to  develop  interesting  modifications  in  the 
fruits  with  which  you  operate,  even  though  you 
devote  only  an  occasional  half -hour  to  the  experi- 
ment. 

You  may  secure  any  amount  of  material  for 
the  development  of  new  varieties  merely  by  plant- 
ing the  first  seeds  of  apple  or  pear  or  plum  that 
come  to  hand.  For  the  cultivated  varieties  of 
orchard  fruits  do  not  breed  true  from  seeds.  You 
will  not  secure  Baldwin  apples,  for  example,  with 
any  certainty,  by  planting  the  seeds  of  the  Bald- 
win. But  this  is  an  advantage  from  the  stand- 
point of  the  plant  experimenter.  You  may  make 
sure  of  interesting  developments  by  planting  the 
seeds  of  any  orchard  fruit  that  you  secure  in  the 

[76] 


BURBANK  IN  THE  ORCHARD 

market,  and  working  with  the  seedlings  along  the 
lines  suggested  above. 

Mr.  Burbank  has  used  the  wild  crab  apple  in 
some  of  his  experiments,  and  has  produced  a 
hybrid  of  large  size,  retaining  certain  qualities  of 
the  wild  fruit.  He  has  also  developed  an  extraor- 
dinary plum,  of  enormous  size  and  of  almost  in- 
credible productivity,  by  hybridizing  the  little 
beach  plum  with  various  cultivated  varieties. 

These  are  experiments  that  you  may  duplicate 
with  very  little  trouble,  the  results  of  which  are 
sure  to  be  surprising  and  fascinating. 

Even  before  the  blossoms  come,  you  may  begin 
operations  by  grafting  scions  of  good  varieties 
on  the  branches  of  your  old  trees.  Also,  you 
should  start  at  once  germinating  some  seeds,  to 
raise  seedlings  that  will  be  grafted  or  budded  on 
your  trees  later  in  the  season. 

If,  in  addition,  you  will  prune  your  old  orchard 
trees  thoroughly,  and  cultivate  and  fertilize  the 
soil  about  their  roots,  you  will  have  prepared  the 
way  for  a  crop  of  improved  fruit  the  coming  fall, 
and  for  a  series  of  fascinating  experiments  in  the 
development  of  new  varieties. 

You  may  plant  the  seeds  at  once  on  taking  them 
from  the  fruit,  as  soon  as  the  fruit  is  ripe  in  the 
fall,  provided  you  have  a  warm  place  in  which 
to  keep  them  over  winter.  Plant  them  in  a  box 
or  can,  in  soil  prepared  according  to  Mr.  Bur- 
bank's  formula  already  given.  They  will  thus 
get  a  good  start,  and  will  be  ready  for  transplant- 
ing or  for  grafting  in  the  early  spring. 

[77] 


LUTHER  BURBANK 

If,  on  the  other  hand,  you  keep  the  seeds  over 
winter,  they  should  be  kept  slightly  moist,  as  they 
will  not  germinate  readily,  if  at  all,  if  they  are 
allowed  to  become  thoroughly  dry.  They  may  be 
kept  in  sand  that  is  slightly  moistened  (not  wet) 
in  a  cool  place.  The  seedlings  grown  from  seeds 
planted  in  the  early  spring  will  be  ready  to  supply 
material  for  summer  budding,  or  they  may  be  left 
on  their  own  roots  throughout  the  season,  to  be 
grafted  early  in  the  succeeding  spring. 

Meantime  you  may  extend  the  scope  of  your 
operations,  and  prepare  for  a  wider  range  of  ex- 
periment next  season,  by  hybridizing  the  flowers 
of  any  orchard  trees  that  chance  to  grow  in  your 
dooryard.  You  may  secure  a  few  apple  blossoms 
from  your  neighbor's  orchard,  and  by  pollenating 
the  blossoms  on  your  own  tree  prepare  the  way 
for  interesting  developments.  Also,  if  trees  are 
at  hand,  try  pollenizing  apple  and  pear,  or  pear 
and  quince,  or  wild  crab  and  cultivated  apple,  or 
wild  plum  and  domestic  plum,  or  wild  cherry  and 
cultivated  cherry. 

There  will  be  no  obvious  immediate  effect  on  the 
flower  that  you  thus  cross-fertilize.  The  fruit  that 
develops  will  be  the  same  in  appearance  that  it 
would  have  been  if  fertilization  had  been  effected 
in  the  ordinary  way  with  pollen  of  its  own  kind. 
But  the  seeds  are  profoundly  affected  in  their 
germinal  matter.  You  must  extract  the  seeds 
when  the  fruit  is  ripe,  and  either  plant  them  at 
once  or  keep  them  over  winter  as  above  suggested. 
The  seedlings  that  grow  from  them  will  be  hybrids 

[78] 


BURBANK  IN  THE  ORCHARD 

combining  the  qualities  of  the  two  parent  forms. 
Just  what  the  result  will  be  cannot  be  known  until 
the  seedlings  are  old  enough  to  bear  fruit, — which, 
if  they  are  properly  grafted,  will  be  in  their 
second  or  third  year.  Then  surprises  will  be  in 
store  for  you.  Not  even  Mr.  Burbank  himself 
could  predict  what  the  new  fruit  may  be  like  in 
a  given  case.  But  it  is  certain  to  be  something 
different  from  either  parent — a  new  form  of  plant 
life  that  you  have  brought  into  being  by  combining 
different  racial  strains. 


[79] 


CHAPTER  V 
NEW  BERRIES  AND  GARDEN  FRUITS 

FEW  aspects  of  Mr.  Burbank's  work  have 
been  more  spectacular  than  those  having 
to  do  with  the  production  of  new  berries. 
He  has  hybridized  the  blackberry  and  the  rasp- 
berry, producing  new  types  of  berry  that  are  en- 
titled to  rank  as  new  species.  He  has  also  hy- 
bridized the  strawberry  and  the  raspberry,  and 
has  crossed  the  dewberry  with  such  divergent 
forms  as  the  apple,  the  pear,  the  mountain  ash, 
and  the  rose.  The  last-named  crosses  produced 
remarkable  plants,  but  these  did  not  bear  fertile 
fruit. 

It  is  quite  within  the  possibilities,  however,  that 
some  other  worker  may  repeat  these  experiments, 
and  produce  berries  as  new  and  wonderful  as  the 
Primus  berry,  the  Phenomenal  berry,  the  Para- 
dox berry,  or  the  white  blackberry,  these  being 
four  of  Mr.  Burbank's  most  wonderful  creations. 

The  way  in  which  these  berries  were  developed 
is  here  told  in  detail ;  also  the  story  of  the  thorn- 
less  blackberry,  the  sunberry,  and  the  improved 
cactus  pear.  The  practical  directions  given  will 
enable  the  amateur  to  improve  any  varieties  of 
berries  in  his  garden  by  selective  breeding,  and 
to  produce  new  varieties  that  are  different  from 

[80] 


A  CLEFT  GRAFT. 

This  reproduction  of  a  color-photograph  illustrates  one  of  several 
common  methods  of  grafting,  as  practiced  in  Mr.  Burbank's  orchard. 
The  engrafted  twigs  are  called  "Scions,"  the  branch  on  which  they 
are  placed  is  called  the  "Stock."  The  essential  principle  is  that  the 
inner  bark,  called  the  Cambium  layer,  of  the  scion,  should  be  brought 
into  intimate  contact  with  the  corresponding  layer  of  bark  of  the 
stock.  The  work  is  completed  by  covering  stock  and  scion  with 
grafting  wax,  and  wrapping  cloth  about  the  stock  for  further  pro- 
tection. 


BERRIES  AND  GARDEN  FRUITS 

any  ever  seen  before,  and  superior  to  anything 
now  in  your  garden,  whether  or  not  they  rival 
the  extraordinary  ones  that  Mr.  Burbank  has 
created. 

CULTURE   OF   GAEDEN   FRUITS 

The  small  fruits  make  a  special  appeal  to  the 
amateur,  because  they  are  so  easily  grown  and 
do  not  demand  so  much  patience  in  awaiting  re- 
sults as  do  the  orchard  fruits. 

Any  odd  corner  of  your  garden  will  afford  op- 
portunity for  a  berry  patch.  Almost  any  soil  will 
do,  but  that  which  is  loose  and  loamy  or  sandy  is 
best. 

It  is  Mr.  Burbank 's  custom  to  plant  the  seeds 
of  raspberries  and  blackberries  as  soon  as  the 
fruit  ripens.  He  merely  crushes  the  fruit  gently, 
washes  away  the  pulp,  and  plants  the  seeds  in 
boxes  which  are  transferred  to  the  greenhouse  in 
the  winter.  They  will  thus  make  an  early  start 
in  the  spring,  and  you  will  gain  several  months' 
time.  If  you  have  not  a  greenhouse  available,  it 
will  be  necessary  to  wait  till  the  following  spring 
before  planting ;  but  the  seeds  are  not  injured  by 
drying. 

If  the  seeds  are  planted  in  boxes,  transplant 
them  when  two  or  three  inches  high  into  rows 
about  three  and  one-half  feet  apart,  the  individual 
plants  being  placed  about  a  foot  apart.  Let  the 
seedlings  run  wild  until  they  come  to  fruiting 
age.  Then  rigidly  destroy  the  plants  that  produce 
inferior  fruit. 

[81] 


LUTHER  BURBANK 

The  plants  selected  for  preservation  may  be 
trained  on  posts  or  trellises,  and  made  to  take  any 
desired  shape  by  nipping  off  the  tips  of  stalk  or 
branches.  The  old  wood  should  be  cut  away  from 
time  to  time.  The  best  plants  may  be  propagated 
by  tips  or  by  suckers. 

REMAKKABLE   HYBKIDS 

The  blackberry  and  raspberry  represent  two 
obviously  related  and  familiar  types  of  fruit,  each 
of  which  has  characteristic  qualities.  But  there 
are  many  species  of  each  group,  and  these  may 
be  interbred  indiscriminately,  offering  the  most 
inviting  opportunities  for  the  creation  of  new 
varieties. 

When  Mr.  Burbank  fertilized  the  dewberry  with 
pollen  from  the  apple,  the  pear,  the  mountain  ash, 
and  the  rose,  he  was  carrying  hybridization  to 
something  like  its  limits.  The  plants  belong  to 
the  same  family,  but  the  dewberry  is  not  of  the 
same  genus  with  any  of  the  others. 

The  fruit  that  formed  was  not  visibly  different 
from  other  dewberries.  But  strange  potentiali- 
ties were  blended  in  the  seeds. 

The  plants  that  grew  from  those  seeds  next 
season  showed  the  most  extraordinary  range  and 
variation  of  vine  and  leaf  and  flower.  A  few  of 
them  formed  berries,  but  in  all  cases  these  berries 
were  without  seeds,  or  the  seeds  lacked  the  germi- 
nating kernel.  In  other  words,  the  strange  hy- 
brids were  infertile.  It  would  appear  that  the 

[82] 


BERRIES  AND  GARDEN  FRUITS 

hereditary  strains  thus  brought  together  were  too 
widely  divergent  for  compromise. 

A  somewhat  similar  result  was  obtained  when 
Mr.  Burbank  brought  pollen  from  a  strawberry 
flower  and  placed  it  on  the  pistil  of  the  flower  of 
a  raspberry.  The  seeds  of  the  raspberry  were 
carefully  preserved,  and  next  season  they  germi- 
nated and  produced  plants  which  at  first  had  all 
the  appearance  of  the  strawberry  plant,  but  which 
subsequently  sent  up  stalks  not  unlike  those  of 
the  raspberry.  The  leaves  of  the  curious  hybrid, 
however,  were  always  trifoliate,  like  the  leaves  of 
the  strawberry. 

The  plants  blossomed,  but  formed  only  abortive 
berries  that  had  no  seeds. 

On  the  other  hand,  when  Mr.  Burbank  fertilized 
the  flower  of  the  dewberry  with  pollen  of  a  rasp- 
berry plant  he  had  imported  from  Siberia,  one 
of  the  numerous  hybrid  offspring  showed  great 
vigor,  having  a  much  larger  leaf  than  either  of 
its  parents,  and  producing  a  fruit  that  also  was 
much  larger  than  that  of  either  parent.  This 
fruit  was  named  the  Primus  berry.  It  has  the 
outward  appearance  of  a  blackberry,  but  if  al- 
lowed to  remain  on  the  vines  until  entirely  ripe, 
it  parts  from  the  receptacle  on  being  picked,  just 
as  a  raspberry  does. 

The  Primus  berry  is  a  hybrid  of  the  first  gen- 
eration, which  appears  to  blend  the  qualities  of 
its  parents  in  about  equal  proportions.  Curiously 
enough  it  did  not  revert  to  the  form  of  either 
parent  in  the  next  generation,  though  thousands 

[83] 


LUTHER  BURBANK 

of  seedlings  have  since  been  grown  from  it.  On 
the  contrary,  it  breeds  true  from  the  seeds — as 
true  as  any  wild  species,  and  far  more  true  than 
most  cultivated  ones.  Thus  it  gives  every  evi- 
dence of  constituting  a  fixed  species,  sprung  into 
being  in  a  single  generation. 

This  is  believed  to  be  the  very  first  new  species 
of  plant  ever  produced  under  conscious  human 
direction.  Its  production  marked  an  epoch  in  the 
history  of  plant  development, — not  because  of  the 
qualities  of  the  Primus  berry  itself,  which  is  of 
a  flavor  not  generally  appreciated,  but  because 
of  the  demonstration  that  a  new  species  could 
be  produced  by  hybridization.  Instead  of  being 
infertile  as  hybrids  were  supposed  to  be,  the  new 
berry  proved  enormously  productive. 

Another  variation  in  application  of  the  laws 
of  heredity  was  illustrated  when  Mr.  Burbank 
crossed  the  California  dewberry  and  the  Cuthbert 
raspberry.  Here  the  hybrid  progeny  were  of 
various  forms,  but  they  were  all  red  in  color, 
though  the  seed  parent  was  the  blackberry.  The 
hybrids  proved  fertile,  and  a  few  of  the  best  of 
them  were  preserved  and  inbred  through  suc- 
cessive generations.  In  the  second  generation 
one  of  these  produced  a  berry  of  extraordinary 
size — perhaps  the  largest  berry  ever  seen — which 
resembles  a  blackberry  in  general  appearance  but 
is  bright  clear  red  in  color,  showing  the  influence 
of  the  raspberry  grandparent.  This  berry  was 
named  the  Phenomenal.  It  has  a  fine  flavor  and 
has  gained  great  popularity. 

[84] 


BERRIES  AND  GARDEN  FRUITS 

This  fruit  is  so  different  from  either  raspberry 
or  blackberry  that  the  nurserymen  classify  it  with 
neither,  but  in  a  new  group.  The  combination  is 
so  fixed  that  there  is  never  reversion  to  either 
raspberry  or  blackberry  in  any  generation.  In 
other  words,  the  Phenomenal  berry  also  is  a  new 
species  that  breeds  true. 

The  Paradox  berry  has  for  its  ancestors  the 
Lawton  blackberry  and  the  Crystal  White  black- 
berry. The  hybrid  offspring  of  this  union  were 
selected  and  inbred  through  several  generations, 
and  the  berry  named  the  Paradox  appeared  in  the 
fourth  generation. 

Of  these  three  remarkable  new  species  of  brier 
fruits,  then,  one  is  a  first-generation  hybrid,  an- 
other a  second-generation  hybrid,  and  the  third 
a  fourth-generation  hybrid. 

QUANTITY  PEODUCTION 

It  must  be  understood  that  in  each  case  Mr. 
Burbank  was  dealing  with  large  numbers  of  hy- 
brids, and  that  the  berry  finally  selected  and 
named  was  the  best  individual  in  a  fraternity  that 
included  thousands  or  tens  of  thousands  of  indi- 
viduals. While  the  blackberry-raspberry  experi- 
ments were  under  way,  indeed,  Mr.  Burbank  had 
occasion  each  successive  season  to  select  a  few 
individuals  as  representing  most  nearly  the  ideal 
at  which  he  aimed,  the  remaining  plants  being 
uprooted,  piled  in  a  heap,  and  burned. 

On  one  occasion  no  fewer  than  65,000  hybrid 
[85] 


LUTHER  BURBANK 

plants  of  the  blackberry  and  raspberry  were  thus 
consumed. 

Many  of  these  vines  bore  excellent  fruit,  but 
it  was  impractical  to  sell  them  or  give  them  away, 
because  some  of  the  recipients  would  have  been 
sure  sooner  or  later  to  announce  their  fruits  as 
" Luther  Burbank's  finest  creation,"  to  the  dis- 
advantage of  the  purchaser  and  to  the  detriment 
of  Mr.  Burbank's  reputation.  The  plant  devel- 
oper himself  never  puts  a  new  variety  on  the 
market  unless  he  believes  it  to  be  superior  to  any 
existing  variety  in  at  last  one  respect,  and  equal 
to  any  other  in  all  respects.  His  reputation  has 
been  made  by  following  this  rule,  and  he  cannot 
afford  to  jeopardize  it  by  allowing  any  new  va- 
riety that  does  not  conform  to  this  test  to  be  put 
on  the  market. 

Hence   the   necessity   for  the   not   infrequent 
" ten-thousand-dollar  bonfires"  through  which  the 
discarded  plants  that  have  entered  into  his  experi- 
ments are  destroyed. 
'  '"—»•*£?  * 

When  we  learn  that  the  original  Paradox  berry 

vine  was  the  only  individual  saved  among  forty 
thousand  hybrids,  our  first  thought  is  likely  to 
be  that  it  is  an  almost  hopeless  task  for  the  ama- 
teur to  attempt  to  develop  a  new  variety  of  small 
fruit. 

But  it  should  be  explained  that  the  standard 
of  the  amateur  need  not  be  so  high  as  the  standard 
that  Mr.  Burbank  establishes.  Among  the  forty 
thousand  discarded  vines  there  were  doubtless 
large  numbers  producing  new  varieties  of  berries 

[86] 


BERRIES  AND  GARDEN  FRUITS 

that  would  have  been  highly  satisfactory  to  almost 
any  other  experimenter. 

Mr.  Burbank  was  looking  for  the  one  best  berry, 
and  he  took  no  interest  in  a  second-best. 

The  amateur  who  is  experimenting  for  his  own 
pleasure  rather  than  for  the  production  of  com- 
mercial fruits  may  well  be  satisfied  if  he  produces 
varieties  differing  from  any  others  hitherto  in  ex- 
istence, even  though  these  new  varieties  should 
not  chance  to  be  of  superlative  quality  under  gen- 
eral culture.  Yet  it  might  be  your  good  fortune 
to  produce  a  new  fruit  of  distinction  at  the  very 
outset.  In  any  event,  you  may  without  question 
improve  the  quality  of  any  fruit  in  your  garden 
if  you  will  follow  the  methods  that  Mr.  Burbank 
has  developed.  You  may  grow  better  berries  than 
you  ever  grew  before,  and  different  ones  from 
those  of  your  neighbor,  with  no  great  effort — once 
you  know  how. 


NEW   VAEIETIES   TO   ORDER 

The  production  of  new  varieties  of  genuine  im- 
portance lies  well  within  your  grasp  if  you  are 
willing  to  take  the  slight  trouble  involved  in  hy- 
bridizing different  species  of  small  fruits — fol- 
lowed by  rigorous  and  persistent  selection.  For 
that  matter,  it  is  not  necessary  to  do  pollenizing, 
as  the  pioneer  work  has  already  been  done  with 
most  of  our  small  fruits,  and  selection  alone,  sys- 
tematically followed  up,  will  bring  interesting  re- 
sults. Mr.  Burbank 's  remarkable  Himalaya  berry 

[87] 


LUTHER  BURBANK 

was  produced  by  selection,  from  seeds  imported 
from  India. 

Should  you  wish  to  stimulate  further  variation, 
however,  you  may  practice  cross-pollenizing.  The 
method  has  been  explained  in  connection  with 
orchard  fruits,  and  need  not  be  repeated  here. 
The  only  essential,  it  will  be  recalled,  is  the  trans- 
fer of  pollen  from  one  flower  to  the  pistil  of  an- 
other at  a  time  when  the  pistil  is  mature,  or  ap- 
proaching maturity. 

The  fruit  in  itself  that  grows  from  the  flower 
thus  cross-fertilized  will  not  reveal  the  character 
of  the  pollen  parent.  If,  for  example,  pollen  has 
been  brought  from  a  blackberry  flower  to  fertilize 
a  raspberry,  the  raspberry  fruit  will  be'  the  same 
in  appearance  as  it  would  have  been  if  the  flower 
had  been  fertilized  with  pollen  from  another  rasp- 
berry. 

But  the  seeds  in  the  fruit  will  be  profoundly 
changed  in  nature,  though  in  no  way  altered  in 
exterior  appearance,  and  the  vines  that  grow  from 
them  next  season  may  show  at  once  the  evidence 
of  their  hybridity.  Just  what  will  be  the  char- 
acter of  the  fruit  they  will  bear  can  never  be 
predicted,  and  this  uncertainty  gives  added  in- 
terest to  the  experiment. 

As  a  rule,  it  is  well  in  hybridizing  two  plants  to 
make  what  is  called  a  reciprocal  cross — that  is  to 
say,  use  pollen  from  each  plant  to  fertilize  flowers 
of  the  other  plant.  But  it  is  the  general  experi- 
ence that  the  hybrid  offspring  have  the  same  char- 
acteristics whichever  way  the  cross  is  made. 

[88] 


CULTIVATING  THE  FRUIT  ORCHARDS 

The  view  is  taken  at  Sebastopol.  It  shows  modern  fruit  trees  trained  to 
such  manner  of  growth  that  they  permit  the  plow  to  run  close  to  their  trunks. 
This  is  an  experimental  orchard,  and  the  trees  are  planted  closer  than  they 
would  be  in  a  commercial  orchard,  giving  opportunity  for  abundant  selection 


BERRIES  AND  GARDEN  FRUITS 

Mr.  Burbank's  experiments  show  that  it  is  pos- 
sible to  effect  hybridization  between  all  the  dif- 
ferent varieties  of  blackberries  and  raspberries, 
and  that  interesting  new  varieties  are  produced  in 
almost  endless  profusion.  There  is  perhaps  no 
other  field  that  offers  a  readier  opportunity  for 
interesting  experiments.  Anyone  who  has  a  few 
bearing  plants  of  the  blackberry  or  raspberry  in 
his  garden  has  an  equipment  adequate  for  all  his 
needs. 

If  you  have  plants  of  a  single  variety  only,  you 
may  readily  secure  pollen  of  another  variety  from 
the  plants  of  a  neighbor,  and  thus  an  experiment 
may  be  inaugurated  that  is  almost  certain  later 
to  produce  fascinating  developments. 

It  is  even  within  the  possibilities  that  you  may 
produce  a  berry  as  unique  and  remarkable  as 
Mr.  Burbank's  Primus  or  his  Phenomenal  or  his 
Himalaya.  Short  of  that,  you  are  certain  to  de- 
velop hybrid  forms  that  differ  in  some  respect 
from  either  parent.  And  the  novelty  of  having 
a  berry  that  is  different  from  anything  ever  seen 
before  will  be  adequate  reward  for  the  compara- 
tively small  effort  involved. 

It  is  stimulative  to  recall  that  the  Loganberry, 
representing  a  new  type  of  fruit  that  has  found 
its  way  into  thousands  of  gardens,  was  a  chance 
hybrid  between  a  raspberry  and  a  blackberry 
cross-fertilized  by  the  bees.  If  an  insect  can  thus 
create  a  remarkable  new  species,  what  may  not 
you  hope  to  accomplish? 

[89] 


LUTHER  BURBANK 

SOME   PRACTICAL   HINTS 

In  developing  a  hybrid  you  must  of  course  grow 
the  plant  from  the  seed — preferably  planted  fresh 
from  the  berry  as  already  suggested.  But  when 
you  have  secured  a  plant  that  bears  fruit  of  ex- 
ceptional character,  you  may  propagate  it  in- 
definitely by  root  division,  or,  as  already  stated, 
by  tips  or  suckers. 

Thus  you  may  stock  your  garden  with  any  new 
variety  you  develop,  regardless  of  whether  it  will 
breed  true  from  the  seed.  But  of  course  if  you 
wish  to  accomplish  further  improvement  you  must 
make  further  selection  and  grow  other  seedlings ; 
and  from  this  second  selection  after  crossing  your 
best  results  are  likely  to  be  obtained. 

Variations  appear  only  among  seedlings, — ex- 
cept in  rare  cases  of  "bud  sports," — and  variation 
is  the  basis  of  all  plant  improvement. 

You  will  do  well,  then,  to  study  the  character- 
istics of  the  different  plants  in  your  garden,  and 
select  for  further  experiment  those  that  show 
some  variation  that  appeals  to  you, — prolific  bear- 
ing, or  early  bearing,  or  large  size  of  fruit,  or  de- 
liciousness  of  flavor. 

Whatever  the  quality,  you  may  confidently  ex- 
pect that  it  will  be  reproduced  and  accentuated 
in  some  individuals  of  the  progeny  of  the  plant 
grown  from  the  seed.  By  selecting  the  best  of  the 
offspring,  in  the  same  way,  to  furnish  seed  for 
yet  another  generation,  you  may  presently  develop 
a  variety  that  has  the  particular  quality  in  ques- 

[90] 


BERRIES  AND  GARDEN  FRUITS 

tion  as  one  of  its  most  pronounced  attributes — 
although  the  specimen  with  which  your  experi- 
ment began  may  have  shown  only  the  faintest 
trace  of  it. 

You  may  thus  develop  a  new  flavor,  for  ex- 
ample. Or  you  may  double  or  quadruple  the  size 
of  the  fruit.  The  secret  of  success  is  to  select 
rigidly  plants  that  show  variation,  and  breed  from 
them. 

One  very  important  thing  to  understand,  how- 
ever, is  that  your  selection  should  be  based  not 
on  an  individual  berry,  but  on  the  average  product 
of  a  vine.  A  single  fruit  may  chance  to  grow 
under  exceptional  circumstances — alone  on  a  vine, 
or  particularly  favored  by  light  or  nourishment — 
and  so  may  attain  what  might  be  called  abnormal 
proportions.  Such  a  fruit  is  not  more  likely  to 
produce  large  progeny  than  the  smallest,  meanest 
fruit  on  the  plant.  It  is  heredity  that  counts,  not 
the  peculiarities  of  an  individual  plant. 

But  if  you  find  a  plant  whose  average  product 
is  larger  than  the  ordinary,  you  may  with  con- 
fidence save  the  berries  of  that  plant  for  seed,  and 
you  will  almost  surely  get  some  seedlings  that 
will  bear  berries  even  larger  than  those  of  the 
parent  plant.  Even  if  there  is  not  much  improve- 
ment in  the  first  generation,  there  is  likely  to  be  a 
cumulative  effect  with  successive  generations,  and 
a  time  will  come  when  striking  results  will  be 
apparent. 

Mr.  Burbank  speaks  of  this  cumulative  tendency 
as  "the  momentum  of  variation."  It  has  often 

[91] 


LUTHER  BURBANK 

given  him  remarkable  new  varieties  suddenly, 
after  a  series  of  breeding  experiments  that  for 
a  time  gave  little  promise.  The  ultimate  product 
may  differ  so  widely  from  the  first  form  as  fully 
to  justify  reference  to  it  as  a  "new  creation. " 

There  is  one  other  important  point  to  be  borne 
in  mind  in  developing  a  quality  through  selection 
in  the  way  just  suggested :  namely,  that  you  must 
inbreed  the  plants  that  are  developing  the  new 
quality,  once  the  variation  is  manifest. 

Suppose,  for  example,  you  have  found  a  rasp- 
berry vine  in  your  garden  that  bears  fruit  that 
is  very  large  and  of  exceptional  sweetness.  You 
wish  to  accentuate  these  qualities.  Now,  instead 
of  cross-fertilizing,  you  do  just  the  opposite.  You 
take  pollen  from  a  flower  of  your  choice  vine  and 
carry  it  to  the  pistil  of  another  flower  on  the  same 
vine.  Or  you  bring  pollen  from  a  closely  related 
plant  of  similar  qualities.  This  is  called  inbreed- 
ing, or  "line  breeding." 

You  must  combine  forces,  as  it  were,  and  ac- 
centuate the  quality  that  both  parents  present  in 
exceptional  degree.  By  cross-breeding  (say  at  an 
earlier  stage  of  the  same  experiment)  you  pro- 
moted variation,  and  laid  the  foundation  for  new 
varieties.  By  inbreeding  you  limit  variation,  ac- 
centuate a  given  quality,  and  fix  a  type, — turn- 
ing the  forces  of  the  plant  in  the  desired  direc- 
tion. 

One  method  supplements  the  other,  and  Mr. 
Burbank's  most  successful  experiments  in  plant 
development  always  include  both  methods. 

[92] 


BERRIES  AND  GARDEN  FRUITS 

MAKING   A   WHITE   BLACKBEEEY 

Let  us  see  the  methods  applied  by  Mr.  Burbank 
in  one  or  two  typical  experiments.  Take,  for  in- 
stance, the  case  of  the  white  blackberry.  This  is 
one  of  Mr.  Burbank 's  most  interesting  (though 
not  most  useful)  small-fruit  developments.  We 
may  briefly  trace  its  pedigree. 

It  appears  that  a  small  brownish-white  black- 
berry was  found  growing  wild  in  the  eastern 
states,  and  introduced  by  a  New  Jersey  firm  a 
good  many  years  ago  as  a  curiosity,  under  the 
name  of  the  Crystal  White  blackberry.  Notwith- 
standing the  name  given  it,  the  fruit  was  by  no 
means  white,  and  it  was  of  very  inferior  quality 
as  to  size  and  flavor. 

It  occurred  to  Mr.  Burbank,  however,  that  he 
might  be  able  to  improve  the  quality  of  the  fruit 
and  remove  its  traces  of  brownish  pigment. 

In  attempting  to  accomplish  this,  Mr.  Burbank 
hybridized  the  little  berry  with  the  Lawton  black- 
berry. The  hybrid  offspring  all  bore  berries  that 
were  black  in  color.  In  the  second  generation, 
however,  there  appeared  a  small  proportion  of 
vines  that  bore  fruit  that  was  almost  white,  and 
yet  was  of  fair  quality. 

These  vines,  being  inbred,  gave  in  the  next  gen- 
eration berries  that  were  pure  white  and  of  large 
size  and  excellent  flavor. 

What  had  happened,  in  effect,  was  that  the  good- 
fruiting  qualities  of  one  ancestor  had  been  com- 
bined with  the  unpigmented  fruit  of  another 

[93] 


LUTHER  BURBANK 

strain;  and  this  was  precisely  the  combination 
that  the  plant  developer  was  seeking.  Meantime 
the  cross-breeds  varied  widely,  and  some  of  them 
showed  a  tendency  to  vigorous  growth  and  pro- 
lific bearing.  Of  course,  there  were  numberless 
others  that  showed  undesirable  combinations,  but 
these  were  destroyed,  and  only  the  plants  having 
the  desired  qualities  in  the  best  possible  combina- 
tion were  preserved.  By  inbreeding  these  for  a 
few  generations,  the  new  qualities  were  accentu- 
ated and  fixed,  and  a  race  of  white  blackberries 
which  always  come  true  from  the  seed  was  estab- 
lished. 

Let  it  be  particularly  noted  here  that  the  new 
berry,  as  finally  developed  by  selection,  combines 
the  traits  of  two  widely  different  ancestral  strains 
and  accentuates  them,  while  eliminating  other  an- 
cestral traits.  It  has  the  juiciness  and  sweetness 
of  flavor  of  the  Lawton  blackberry ;  and  it  is  snow- 
white,  whereas  one  of  its  ancestors  was  black  and 
the  other  a  brownish-white.  By  selective  breed- 
ing, all  trace  of  pigment  has  been  eliminated  from 
the  species. 

It  will  be  obvious  that  this  selecting  out  of  cer- 
tain qualities  from  different  ancestral  strains  and 
reasserting  them  in  a  hybrid  progeny,  with  the 
elimination  of  other  ancestral  traits,  is  a  very  in- 
teresting and  very  remarkable  phenomenon.  Mr. 
Burbank  early  discovered  that  it  is  possible  thus 
to  segregate  the  qualities  of  different  parents  and 
recombine  them,  accentuated,  in  the  hybrids  of  a 
second  and  a  few  subsequent  generations.  The 

[94] 


BERRIES  AND  GARDEN  FRUITS 

application  of  this  principle  enabled  him  to  pro- 
duce a  large  number  of  his  most  important  new 
varieties  of  all  kinds  of  plants.  He  decides  in 
advance  what  qualities  he  wishes  to  perpetuate 
and  what  ones  he  wishes  to  eliminate,  and  by 
selecting  among  large  numbers  of  seedlings  he 
is  enabled  to  secure  the  ideal  plant  that  he  has 
in  mind. 

But  it  must  not  be  supposed  that  Mr.  Burbank's 
success  is  due  merely  to  the  recombining  of  desired 
fruit  characters  already  present  in  one  parent  or 
the  other.  On  the  contrary,  such  segregation  and 
recombination  of  traits  constitutes  only  the  begin- 
ning of  his  task.  This  does,  indeed,  supply  him 
with  varying  material  with  which  to  work ;  but  as 
a  rule  he  would  not  produce  a  fruit  of  commercial 
value  did  he  not  extend  the  experiment  by  se- 
lective breeding  among  the  individuals  that  have 
the  desired  quality  in  the  most  pronounced  degree. 
Line  breeding  them  intensifies  these  qualities ;  so 
that,  for  example,  the  Burbank  white  blackberry 
is  snow-white,  whereas  its  so-called  "  white "  an- 
cestor was  dull  brownish-white,  and  at  the  same 
time  it  has  the  excellent  qualities  of  the  Lawton. 

THE   THOBNLESS   BLACKBEEBY 

It  was  through  application  of  the  same  princi- 
ples that  Mr.  Burbank  was  enabled  to  develop  his 
wonderful  thornless  blackberry,  perhaps  the  most 
important  of  his  plant  developments  in  this  par- 
ticular field.  Anyone  who  has  had  experience  of 

[95] 


LUTHER  BURBANK 

a  brier  patch  will  readily  conceive  that  the  pro- 
duction of  a  thornless  brier  is  a  work  of  genuine 
importance. 

Mr.  Burbank's  thornless  blackberries,  as  al- 
ready stated,  have  absolutely  smooth  stems. 
There  is  not  the  remnant  of  a  thorn  anywhere 
about  them.  They  are  as  smooth  as  pussy-willows. 
They  are  the  forerunners  of  a  race  of  thornless 
brambles  that  will  doubtless  supplant  the  old 
thorny  kind  everywhere  in  the  near  future. 

The  parent  form  with  which  Mr.  Burbank 
worked  in  producing  these  anomalous  plants  was 
a  nearly  thornless  but  otherwise  worthless  dew- 
berry that  was  discovered  growing  wild  in  North 
Carolina.  The  botanist  who  discovered  the  plant 
gathered  some  of  its  fruit  and  sent  it  to  Mr.  Bur- 
bank,  thinking  he  might  care  to  experiment  with 
it.  The  fruit  in  question  was  of  poor  quality  and, 
as  in  the  case  of  the  white  blackberry,  it  was  neces- 
sary to  breed  altogether  new  qualities  into  it. 

The  problem,  of  course,  was  how  to  retain  and 
accentuate  the  tendency  to  thornlessness  of  plant 
that  was  the  sole  recommendation  of  this  par- 
ticular variety  of  dewberry,  and  at  the  same  time 
to  place  berries  of  good  commercial  qualities  on 
these  plants. 

When  the  thornless  dewberry  was  hybridized 
with  other  blackberries,  the  hybrid  offspring 
were  all  thorny,  just  as  the  offspring  of  the  black 
and  the  white  blackberries  were  all  black.  But 
thornless  progeny  reappeared  in  the  second  gen- 
eration, and  some  of  these  bore  fruit  of  a  better 

[96] 


THE  PROCESS  OP  GRAFTING  COMPLETED 

After  the  scions  are  inserted,  grafting  wax  is  applied,  and  the  end  of  the 
stock  is  bound  up  with  cloth,  to  give  it  added  protection  while  its  wounds  are 
healing. 


LUTHER  BURBANK 

veloped  by  Mr.  Burbank  from  seed  imported  from 
India,  and  hence  named  the  Himalaya  berry.  A 
single  plant  may  produce  several  hundred  pints 
of  berries  in  a  season.  But  the  vine  is  armed  with 
very  stout  recurved  thorns,  making  the  gathering 
of  the  berries  a  somewhat  difficult  and  decidedly 
disagreeable  task. 

It  should  be  possible  by  hybridizing  this  plant 
with  the  thornless  blackberry  to  produce  in  a  later 
generation  a  plant  combining  the  vigorous  growth 
and  prolific  bearing  of  the  Himalaya  with  thorn- 
lessness.  Mr.  Burbank  has  made  this  cross,  and 
he  has  also  crossed  the  thornless  blackberry  with 
the  white  blackberry.  He  has  many  thousands  of 
seedlings  of  both  type  now  under  test  that  will 
give  new  varieties  of  thornless  berries  when  fully 
educated.  He  has  also  seedlings  from  a  new 
cross  of  the  Japanese  Balloon-berry  and  a  rasp- 
berry from  Hawaii,  and  scores  of  other  berry 
seedlings  of  new  combinations. 

It  is  not  unlikely  that  in  the  course  of  these 
experiments  there  will  develop  berries  with  quite 
unpredicted  qualities.  For  Mr.  Burbank  has 
shown  over  and  over  that  where  plants  from 
widely  separated  geographical  regions  are 
brought  together  the  offspring  are  likely  to  mani- 
fest extraordinary  vigor,  and  to  reveal  traits  of 
the  most  unexpected  character. 

The  hybrid  seedlings  of  the  Balloon-berry  and 
the  Hawaiian  raspberry  grow  so  rapidly  as  soon 
to  overshadow  their  parents.  Such  enhanced 
capacity  for  growth  is  shown  by  various  of  Mr. 

[98] 


BERRIES  AND  GARDEN  FRUITS 

Burbank 's  berry  hybrids  and  often  extends  to  the 
fruit  itself,  as  in  the  case  of  the  Primus  berry 
and  the  Phenomenal  berry,  already  noted. 

So  there  is  every  prospect  that  any  hybridizing 
experiments  you  may  undertake  with  blackberries 
or  raspberries  in  your  garden  will  produce  new 
races,  a  certain  proportion  of  the  individuals  of 
which  will  excel  the  parent  forms  very  markedly 
in  vigor  of  growth  and  in  size  of  fruit. 

OTHEB  SMALL  FRUITS  THAT  AWAIT  DEVELOPMENT 

Doubtless  the  blackberries  and  raspberries  offer 
the  most  inviting  opportunities  for  experiment, 
yet  we  must  by  no  means  overlook  the  other  small 
fruits  that  are  to  be  found  in  the  amateur's  gar- 
den. The  strawberry,  for  example,  may  be  hy- 
bridized quite  as  readily  as  the  other  berries.  In 
particular  it  would  be  well  worth  while  to  repeat 
Mr.  Burbank 's  experiment  of  cross-pollenizing  the 
strawberry  and  the  raspberry.  A  similar  cross 
might  be  attempted  with  the  blackberry,  now  that 
Mr.  Burbank  has  developed  a  strawberry  that 
bears  throughout  the  season.  Hitherto  it  would 
have  been  difficult  to  find  strawberries  and  black- 
berries blossoming  at  the  same  time. 

It  is  true  that  Mr.  Burbank 's  celebrated  experi- 
ment in  crossing  the  strawberry  and  the  raspberry 
produced  only  infertile  hybrids.  But  it  is  quite 
within  the  possibilities  that  greater  success  might 
attend  another  series  of  experiments.  And  it  re- 
quires no  argument  to  show  that  a  fruit  that  com- 

[99] 


LUTHER  BURBANK 

bines  the  qualities  of  the  strawberry  and  the  rasp- 
berry would  be  a  very  valuable  and  interesting 
acquisition. 

If  you  will  take  the  trouble  to  fertilize  the 
flowers  of  the  raspberry  and  blackberry  with 
pollen  of  the  strawberry  (it  would  be  well  to  make 
the  reciprocal  crosses  also)  it  may  fall  to  your  lot 
to  produce  a  fertile  hybrid  that  will  be  as  unique 
and  remarkable  an  addition  to  the  list  of  small 
fruits  as  is,  for  example,  Mr.  Burbank's  plumcot 
among  orchard  fruits. 

Again,  we  must  not  overlook  the  currants  and 
gooseberries.  These  have  small  flowers,  and 
hence  are  not  quite  so  easy  to  work  with.  But 
with  the  aid  of  a  magnifying-glass  they  may  read- 
ily be  cross-pollenized,  and  there  is  ample  oppor- 
tunity for  the  development  of  new  varieties.  It 
is  particularly  desirable,  for  example,  that  goose- 
berries should  be  developed  that  are  without  the 
disagreeable  hairs  or  prickles  that  most  varieties 
of  this  fruit  bear,  also  without  thorns  on  the 
bushes.  A  sweet  and  high-flavored  gooseberry 
would  also  be  welcomed.  Plants  that  are  resistant 
to  mildew  are  also  to  be  desired. 

Mr.  Burbank  has  shown  that  the  different  cur- 
rants and  gooseberries  may  be  cross-fertilized 
readily.  There  are  numerous  varieties  under  cul- 
tivation that  may  be  used  in  hybridizing  experi- 
ments, and  there  are  also  wild  species  to  be  found 
in  many  regions  that  might  advantageously  be 
tested.  In  many  cases  a  wild  species  has  qualities 
of  hardiness  and  vigorous  growth  that  may  ad- 

[100] 


BERRIES  AND  GARDEN 

vantageously  be  blended  with  the  size  and  flavor 
of  fruit  of  the  cultivated  varieties. 

So  it  might  be  possible,  by  hybridizing  the  cur- 
rants and  gooseberries  with  wild  species,  to  pro- 
duce new  types  of  berries  that  would  retain  the 
attractive  qualities  of  the  currant,  yet  would  be 
as  large,  let  us  say,  as  cherries.  Here  again  the 
field  is  one  that  any  amateur  may  readily  enter, 
now  that  Mr.  Burbank  has  shown  the  way. 

A  few  years  ago  it  would  have  been  thought 
ridiculous  to  suggest  that  our  common  fruits 
might  thus  be  modified  and  developed  into  new 
forms  with  comparative  little  effort,  and  in  the 
course  of  two  or  three  generations.  But  Mr.  Bur- 
bank  has  shown  that  such  modifications  may  be 
brought  about,  making  the  demonstration  thou- 
sands of  times  over,  until  no  opportunity  for 
skepticism  remains.  And,  as  already  suggested, 
there  is  perhaps  no  other  field  that  offers  more 
inviting  opportunities  than  those  that  are  to  be 
found  in  the  ordinary  small-fruit  garden. 

SOME   NEW   FEUITS 

As  illustrating  the  possibility  of  making  addi- 
tions to  the  list  of  garden  fruits,  mention  may  be 
made  of  Mr.  Burbank 's  sunberry,  which  is  a  hy- 
brid between  two  forms  of  nightshade,  neither  of 
which  produces  edible  fruit. 

This  new  berry,  which  is  particularly  prized  for 
the  making  of  pies, — it  closely  resembles  the  blue- 
berry in  flavor, — is  a  brand-new  addition  to  the 

[101] 


LUTIIER  BURBANK 

list  of  edible  fruits.  It  was  produced  as  a  fixed 
new  species  in  the  first  generation,  through  hy- 
bridizing two  forms  of  nightshade;  one  of  them 
from  Africa,  the  other  a  weed-like  plant  indige- 
nous to  America  or  long  ago  introduced  from 
Europe.  The  hybrid  is  in  a  good  many  ways  in- 
termediate between  the  parent  forms,  but  it  dif- 
fers from  either  of  them  in  that  its  berries  are 
edible. 

Some  confusion  has  arisen  through  the  change 
of  name,  unauthorized  by  Mr.  Burbank,  which 
led  to  the  placing  of  this  fruit  on  the  market  as 
the  "Wonderberry,"  and  through  the  confusion 
of  the  new  fruit  with  other  species  of  nightshade 
to  which  it  is  only  distantly  related.  The  night- 
shade family,  it  should  be  explained,  has  poison- 
ous members,  and  so  is  of  ill  repute.  But  it  should 
not  be  forgotten  that  among  the  wholesome  repre- 
sentatives of  the  family  are  the  familiar  garden 
vegetables,  the  potato,  the  tomato,  and  the  egg- 
plant. 

From  the  standpoint  of  the  plant  developer, 
perhaps  the  chiefest  interest  associated  with  the 
sunberry  hinges  on  the  fact  that  the  hybridization 
through  which  it  was  created  was  accomplished 
only  after  many  years  of  unsuccessful  effort.  In- 
deed, Mr.  Burbank  had  attempted  to  cross-fertilize 
the  parent  forms,  quite  without  success,  for  some- 
thing like  twenty-five  years,  before  he  at  last  suc- 
ceeded in  fertilizing  a  single  flower  and  producing 
a  single  berry  from  which  the  new  race  was  de- 
veloped. 

[102] 


BERRIES  AND  GARDEN  FRUITS 

Mr.  Burbank  is  constantly  experimenting  with 
other  wild  plants  that  have  more  or  less  inedible 
fruits.  He  has  in  recent  years  conducted  a  very 
elaborate  series  of  investigations  with  different 
varieties  of  elder,  and  is  developing  varieties  that 
produce  berries  very  much  improved  in  size  and 
quality.  He  is  confident  of  producing  a  valuable 
commercial  fruit,  and  the  fact  that  the  elder  is 
a  hardy  ornamental  shrub  gives  added  value  to 
the  experiment. 

Another  line  of  experiment  that  promises  good 
results  is  being  made  with  the  different  species  of 
passion  flower.  This  subtropical  vine  has  been 
chiefly  prized  for  its  flower,  but  it  bears  a  fruit 
that  is  edible,  and  the  quality  of  this  fruit  is  being 
improved  by  cross-breeding  experiments  in  which 
species  from  different  parts  of  the  world  are 
utilized. 

THE  MOST  PROLIFIC  FRUIT-BEARER 

But  by  far  the  greatest  of  Mr.  Burbank  *s  recent 
triumphs  in  the  production  of  new  fruits  is  that 
associated  with  the  development  of  the  fruit  of  the 
cactus,  and  in  particular  those  new  hybrid  cac- 
tuses of  the  genus  Opuntia  that  have  been  relieved 
of  their  spines. 

The  development  of  the  spineless  cactus  through 
a  long  series  of  experiments  in  hybridizing  and 
selection  constitutes  one  of  the  most  remarkable 
of  Mr.  Burbank 's  achievements  in  recent  years. 
The  slabs  of  the  perfected  varieties  are  as  smooth 

[103] 


LUTHER  BURBANK 

as  the  palm  of  the  hand,  and  they  constitute  a 
remarkable  addition  to  the  world's  forage  crop, 
particularly  adapted  to  arid  regions. 

While  developing  these  spineless  races,  Mr. 
Burbank  paid  attention  to  the  fruit  as  well,  and 
he  has  developed  many  varieties  of  cactus  fruit 
varying  in  appearance  and  quality  almost  as 
widely  as  do  the  different  varieties  of  cultivated 
apples  or  pears.  Some  of  the  cactus  fruits  are 
white  in  color,  others  yellow,  yet  others  a  brilliant 
crimson.  The  flesh  is  juicy  and  palatable.  As  yet 
the  prickles  have  not  been  entirely  removed  from 
the  skin  of  the  fruit,  but  Mr.  Burbank  has  plants 
now  under  development  that  he  is  confident  will 
bear  perfectly  smooth  fruit.  It  required  a  little 
longer  to  take  the  spines  off  the  fruit,  because  the 
cactus  does  not  bear  fruit  until  it  is  four  or  five 
years  old,  and  it  was  necessary  to  let  each  suc- 
ceeding generation  come  to  maturity  before  the 
quality  of  its  fruit  could  be  determined. 

Meantime  the  prickly  or  smooth  condition  of 
the  slabs  of  the  plant  could  be  observed  from  the 
outset,  and  selection  for  this  quality  could  be 
made  while  the  seedlings  were  very  small.  But 
in  the  end  the  spines  will  be  removed  from  the 
fruit  as  effectively  as  they  have  been  removed 
from  the  foliage  of  the  plant ;  such,  at  any  rate,  is 
Mr.  Burbank 's  confident  expectation. 

In  the  size  of  its  product,  the  cactus  is  to  be 
compared  with  the  orchard  fruits  rather  than 
with  the  berries.  But  the  cactus,  in  its  perfected 
varieties,  is  admirably  adapted  for  growth  in  the 

[104] 


A  BRAND  NEW  BURBANK  FRUIT— THE  PLUMCOT. 

This  beautiful  reproduction  of  a  direct-color  photograph  shows 
one  of  the  choice  varieties  of  Mr.  Burbank's  new  fruit,  the  Plumcot, 
produced  by  hybridizing  the  plum  and  the  apricot,  and  representing 
the  only  new  type  of  orchard  fruit  that  has  been  developed  within 
historic  times. 


BERRIES  AND  GARDEN  FRUITS 

garden,  and  it  has  many  attractive  qualities.  It 
is  enormously  productive,  thrives  under  the  most 
adverse  conditions,  and  bears  a  fruit  so  different 
from  any  other  of  the  products  of  the  garden  as 
to  have  double  attractiveness. 

A  single  plant  will  bear  all  the  fruit  that  a 
good-sized  family  could  use.  Sometimes  half  a 
hundred  fruits  are  borne  on  a  single  slab.  The 
best  of  Mr.  Burbank's  fruiting  varieties  bears, 
on  good  soil,  at  the  rate  of  more  than  one  hundred 
tons  per  acre. 

Unfortunately  the  new  fruiting  cactus  plants 
are  not  very  hardy,  but  whoever  lives  in  a  region 
to  which  they  are  adapted  will  find  this  a  valua- 
ble addition  to  the  fruit  garden.  Meantime  there 
is  opportunity  for  further  experiment  in  selective 
breeding  with  an  eye  to  the  production  of  hardier 
varieties. 

There  are  varieties  of  cactus  that  thrive  in  the 
coldest  regions,  and  it  is  probable  that  by  using 
these  in  hybridizing  experiments  new  varieties 
might  be  developed  that  combine  the  fruiting 
qualities  of  Mr.  Burbank's  new  cactuses  with  the 
hardiness  of  the  other  parent.  Mr.  Burbank  him- 
self has  experiments  under  way  looking  to  this 
end,  but  there  is  no  reason  why  his  efforts  should 
not  be  supplemented  by  those  of  many  other 
workers. 

The  cactus  is  a  comparatively  easy  plant  to 
hybridize,  its  flowers  being  large  and  conspicuous. 
It  is  necessary,  however,  to  watch  the  flowers 
closely  and  cross-fertilize  them  at  once  when  they 

[105] 


LUTHER  BURBANK 

open,  before  the  bees  have  time  to  forestall  your 
efforts. 

Except  for  the  development  of  new  varieties, 
the  cactus  should  not  be  grown  from  the  seed,  as, 
like  other  cultivated  fruit-bearers,  it  does  not 
breed  true.  But  the  slabs  take  root  readily, — 
especially  if  dried  somewhat  before  planting, — 
and  the  plant  may  thus  be  propagated  indefinitely, 
all  the  offshoots  reproducing  the  qualities  of  the 
parent  form. 


[106] 


CHAPTER  VI 
BUEBANK  IN  THE  VEGETABLE  GAEDEN 

IN  this  chapter  are  detailed  the  methods  of 
selective  breeding  through  which  improved 
types  of  vegetables  of  many  kinds  may  be 
produced  in  your  garden. 

Among  the  most  remarkable  of  Mr.  Burbank's 
experiments  were  those  in  which  he  grafted  to- 
mato plants  on  roots  of  potatoes  and  potato  vines 
on  roots  of  tomato  vines.  The  resulting  fruits 
and  tubers  were  extraordinary  and  unlike  any- 
thing seen  before.  These  experiments  may  be  re- 
peated by  anyone  who  will  follow  out  the  com- 
paratively simple  methods  of  grafting  described. 
The  feat  of  hybridizing  the  blossoms  of  potato 
and  tomato  has  not  yet  been  accomplished,  but 
this  is  among  the  possibilities,  and  the  results  are 
sure  to  be  extraordinary. 

The  members  of  the  squash  and  melon  family 
offer  interesting  possibilities  of  hybridizing,  and 
these  experiments  may  easily  be  carried  out  by 
anyone.  New  types  of  peas  and  beans  may  readily 
be  produced;  and  experiments  of  a  fascinating 
character  may  be  performed  with  various  varie- 
ties of  sweet  corn.  In  fact,  there  is  scarcely  a 
plant  in  the  vegetable  garden  that  does  not  offer 
opportunities  for  interesting  experiments. 

[107] 


LUTHER  BURBANK 

THE   BUKBANK   POTATO 

Doubtless  you  have  eaten  the  Burbank  potato, 
although  you  may  not  know  it  by  that  name.  Mr. 
Burbank  developed  this  new  variety  when  he  was 
a  very  young  man,  and  it  has  come  to  be  grown  so 
universally  that  most  people  who  cultivate  it  know 
nothing  of  its  origin.  The  Department  of  Agri- 
culture estimated  that  up  to  1906  not  less  than 
seventeen  million  dollars'  worth  of  Burbank  po- 
tatoes had  been  grown  in  the  United  States.  This 
was  Mr.  Burbank  ?s  first  important  plant  develop- 
ment, and  for  that  reason  also  it  has  exceptional 
interest. 

Unlike  many  of  his  later  developments,  the  new 
potato  was  produced  without  the  necessity  for  a 
long  series  of  preliminary  experiments.  It  was, 
in  a  sense,  a  discovery  rather  than  a  creation,  and 
as  such  it  has  added  interest  for  the  amateur, 
inasmuch  as  it  suggests  the  possibility  of  finding 
in  any  garden  extraordinary  things  if  only  we 
search  for  them. 

The  extraordinary  thing  that  Mr.  Burbank 
found  in  his  Massachusetts  garden  when  he  was 
scarcely  more  than  a  boy  (it  happened  in  1873) 
was  a  seed  ball  growing  on  one  of  his  potato 
vines. 

Everyone  knows  that  the  potato  is  propagated 
by  planting  pieces  of  the  tuber  itself,  and  that 
ordinarily  the  potato  vine  does  not  produce  seed. 
In  very  rare  instances,  however,  a  seed  cluster 
does  form,  but  it  requires  the  imaginative  mind 

[108] 


IN  THE  VEGETABLE  GARDEN 

of  a  Burbank  to  conceive  that  there  is  any  im- 
portance in  this  exceptional  phenomenon.  Most 
gardeners  would  have  paid  no  attention  to  the 
seed  ball,  but  Mr.  Burbank  watched  it  attentively, 
and  determined  to  find  out  what  would  happen 
if  the  seeds  were  planted.  His  plan  was  nearly 
frustrated  by  the  loss  of  the  seed  ball,  which  was 
broken  off  by  some  boy  or  animal  or  by  the  wind 
just  as  it  ripened.  After  patient  search  the  treas- 
ure was  recovered,  however,  and  carefully  pre- 
served over  winter. 

There  were  twenty-three  seeds  in  the  cluster, 
and  these  were  planted  next  spring,  each  one  by 
itself,  and  the  vines  that  grew  from  the  seed 
were  carefully  cultivated. 

In  the  fall,  when  the  potatoes  were  dug,  it  was 
obvious  that  they  represented  twenty-three  differ- 
ent varieties.  No  two  hills  were  alike  in  size  or 
appearance  or  abundance  of  their  crop.  And  two 
of  the  hills  bore  potatoes  of  altogether  exceptional 
size  and  quality.  These  were  preserved  and 
planted  another  season,  and  it  was  demonstrated 
that  the  tubers  would  reproduce  their  qualities, 
constituting  a  new  variety,  larger  in  size,  whiter, 
smoother,  and  more  uniform  in  shape  than  any 
existing  variety. 

To  illustrate  the  element  of  chance  that  enters 
into  the  work  of  the  plant  developer,  it  may  be 
added  that  whereas  the  remarkable  Burbank  po- 
tato was  thus  developed  in  a  single  season  merely 
by  planting  seeds  that  developed  quite  inde- 
pendently of  human  effort,  forty  years  of  subse- 

[109] 


LUTHER  BURBANK 

quent  effort,  in  which  vast  numbers  of  hybridizing 
experiments  have  been  performed,  have  failed  to 
produce  another  variety  of  potato  superior  to  the 
one  that  was  virtually  a  gift  of  nature.  In  this 
field  of  endeavor,  as  in  so  many  others,  there  is  an 
element  of  uncertainty  that  adds  to  its  charm. 

Very  recently,  however,  Mr.  Burbank  has  ex- 
perimented with  wild  species  of  potato  from  South 
America,  and  has  produced  some  remarkable  new 
varieties  that  are  about  to  be  introduced. 

MAKING  A  PEA   TO   OKDER 

As  illustrating  about  as  striking  a  contrast  to 
the  story  of  the  potato  as  could  be  found,  we 
might  cite  the  story  of  the  Empson  pea. 

Mr.  Burbank  was  asked  by  a  canner  of  peas  to 
produce  a  new  variety  in  which  the  individual  peas 
would  be  small  but  uniform  in  size ;  in  which  they 
would  be  uniform  as  to  number  in  the  pod;  and 
would  mature  at  the  same  time,  so  that  the  entire 
crop  could  be  gathered  at  once,  it  being  the  method 
in  the  modern  cannery  to  cut  the  vines  by  ma- 
chinery, carting  them  to  the  cannery  like  loads  of 
hay.  Of  course  it  was  essential  that  the  peas 
should  retain  their  quality  of  sweetness  of  flavor, 
and  that  the  vines  should  bear  an  abundant  crop 
of  pods. 

Mr.  Burbank  was  able  to  meet  these  specifica- 
tions in  a  period  of  only  three  years,  by  raising 
two  crops  of  peas  each  season.  And  he  did  this 
purely  by  selection,  raising  large  quantities  of  the 

[110] 


IN  THE  VEGETABLE  GARDEN 

vines,  and  searching  attentively  among  them  for 
the  individual  vine  that  bore  a  crop  coming  nearest 
to  the  specifications.  All  the  other  vines  were  de- 
stroyed, and  the  new  races  of  peas  finally  devel- 
oped were  descendants  of  the  one  best  vine.  In 
each  succeeding  generation  the  inferior  vines  were 
similarly  destroyed,  and  the  best  individual  speci- 
mens preserved. 

The  vines  of  the  sixth  generation  were  prac- 
tically uniform  and  met  the  specifications  as  to 
abundant  crop  of  peas  of  designated  size  and 
quality,  maturing  at  the  same  time. 

But  while  Mr.  Burbank  was  developing  this  new 
race  of  peas,  he  developed  also  from  the  same 
set  of  vines  four  other  races,  some  of  them  bear- 
ing large  peas,  others  lentil-shaped  ones,  merely 
by  selecting  generation  after  generation  with 
these  qualities  in  mind. 

The  point  is  simply  that  in  any  row  of  peas  in 
your  garden,  grown  from  the  same  lot  of  seed, 
there  is  a  wide  range  of  variation,  which  the  aver- 
age gardener  quite  ignores. 

But  the  attentive  eye  notes  that  some  vines  grow 
abundant  crops  and  others  scanty  crops;  that 
some  of  the  pods  are  large  and  some  small;  and 
that  as  regards  almost  any  given  quality  of  the 
pea  there  is  diversity,  even  though  the  peas  are 
all  classified  as  belonging  to  the  same  variety. 

If  you  will  select  and  save  separately  the  peas 
from  half  a  dozen  different  vines,  you  may  de- 
velop as  many  different  races  of  peas  in  the  course 
of  a  few  generations.  You  may  produce  a  variety 

[111] 


LUTHER  BURBANK 

of  predicted  quality,  as  Mr.  Burbank  did  in  the 
case  of  the  canning  peas,  or  you  may,  as  it  were, 
follow  where  the  peas  lead  you,  and  let  the  po- 
tentialities of  the  different  varieties  reveal  them- 
selves as  you  proceed. 

SELECTION   WITHOUT   CEOSSING 

This  important  point  must  be  borne  in  mind, 
however — and  it  applies  not  merely  to  peas  but  to 
all  other  plants.  In  making  your  selection,  it  is 
necessary  to  consider  the  total  product  of  a  given 
plant,  not  merely  an  individual  fruit.  A  single 
pod  of  peas  may  be  of  exceptional  size  because  it 
chanced  that  it  is  the  only  pod  on  a  vine,  or  be- 
cause some  other  accidental  circumstance  favored 
it.  The  progeny  of  these  peas  will  not  necessarily 
tend  to  produce  a  race  of  large  peas.  But  if  you 
find  a  vine  that  produces  pods  that  are  uniformly 
of  large  size,  this  will  indicate  that  the  tendency 
to  produce  peas  of  this  character  is  in  the  heredity 
or  germ-plasm  of  this  particular  vine,  and  will 
tend  to  be  transmitted. 

It  should  be  observed  that  in  producing  these 
new  varieties  of  peas  Mr.  Burbank  worked  purely 
by  selection,  without  finding  it  necessary  to  hy- 
bridize the  plants  to  produce  new  tendencies  to 
variation. 

The  plants  tended  to  vary  sufficiently  to  give 
him  material  for  his  experiments,  and  such  is 
found  to  be  the  case  with  a  very  large  number  of 
plants  in  the  yegetable  garden. 

[112] 


MR.  BURBANK'S  PHENOMENAL  BERRY 

This  remarkable  berry   is  virtually  a   new  species   produced  by  hybridizing  the 
California   dewberry    and    the    Cuthbert    blackberry. 


IN  THE  VEGETABLE  GARDEN 

Quite  generally  you  will  find  that  there  is  a 
wide  range  of  variation  in  the  plants  grown  from 
the  same  lot  of  seed,  and  you  may  develop  new 
varieties  merely  by  selecting  those  individuals 
that  exhibit  the  desired  quality,  saving  their  seed 
and  selecting  again  for  the  same  quality  among 
the  progeny. 

In  the  case  of  the  pea,  and  its  cousin  the  bean, 
the  experiment  is  simplified  by  the  fact  that  the 
plants  are  normally  self -fertilized.  If  you  will 
examine  the  flower  of  the  pea  or  bean  you  will  see 
that  its  stamen  and  pistil  are  encased  in  a  closed 
floral  envelope,  to  the  interior  of  which  bees  and 
other  insects  cannot  readily  gain  access.  Nor- 
mally each  pistil  is  fertilized  by  pollen  from  the 
stamens  that  grow  beside  it. 

In  other  words,  there  is  the  closest  inbreeding, 
and  there  is  no  danger  of  introducing  varying 
strains  of  other  plants  by  cross-fertilization. 

The  case  is  radically  different,  for  example, 
from  that  of  the  squashes  and  melons,  which  are  so 
readily  cross-fertilized  that  it  is  exceedingly  dif- 
ficult to  keep  the  strains  of  any  variety  pure  if 
other  varieties  are  grown  anywhere  in  the  neigh- 
borhood. The  bees  are  almost  certain  to  carry  the 
pollen  of  one  kind  of  melon  or  squash  to  the  pistil 
of  another,  bringing  the  pollen  perhaps  from 
flowers  a  quarter  of  a  mile  away;  so  you  will  ex- 
perience constant  disappointment  in  growing 
crops  of  melons  or  squashes  from  the  seed,  unless 
you  carefully  shield  the  blossom  from  such  con- 
tamination through  cross-pollenizing. 

[113] 


LUTHER  BURBANK 

If  you  wish  to  keep  your  strain  of  melons  or 
squashes  pure,  you  should  carry  pollen  from  one 
flower  to  another  with  the  finger  tip  or  with  a 
camePs-hair  brush,  and  then  cover  the  flowers 
with  a  paper  sack  until  they  are  past  the  time  of 
receptivity. 

On  the  other  hand,  if  you  wish  to  experiment 
with  varying  races  of  melons  or  squashes,  you 
have  but  to  leave  the  work  of  cross-fertilization 
to  the  bees,  and  your  seeds  next  season  will  give 
you  as  strange  and  variant  a  lot  of  material  as 
you  could  desire.  But  there  is  no  such  difficulty 
with  the  peas  and  beans.  These,  as  just  stated, 
are  protected  against  cross-fertilization  by  the 
character  of  their  flower,  and  thus  it  is  compara- 
tively easy  to  maintain  a  pure  strain,  once  it  is 
established. 

HYBEIDIZING  PEAS   AND   BEANS 

If  you  wish,  however,  to  extend  your  experi- 
ments with  peas  and  beans,  causing  them  to  vary 
and  thus  to  supply  new  material  for  selection,  you 
may  readily  do  so  by  the  method  of  artificial 
pollenation.  For  although  the  floral  envelope  is 
closed  against  the  bee,  you  may  readily  enough 
open  it,  and  the  pollenizing  of  the  flower  then  pre- 
sents no  difficulties.  You  may  pluck  away  the 
stamens  and  deposit  pollen  from  another  flower 
on  the  pistil,  precisely  as  you  would  do  in  the 
case  of  any  other  blossom. 

Tie  a  string  loosely  about  the  stem  on  which 
[114] 


IN  THE  VEGETABLE  GARDEN 

this  blossom  grows,  with  a  label  naming  the  va- 
riety used  as  the  pollen  parent,  and  preserve  the 
seeds  for  planting  next  season. 

Some  of  the  most  interesting  and  important 
plant  experiments  have  been  made  with  the  gar- 
den pea  in  this  way,  notably  the  celebrated  ex- 
periments of  the  Austrian  monk,  Mendel,  which 
led  to  his  discovery  that  some  characters  are 
"  dominant "  and  others  "  recessive "  in  heredity, 
and  that  the  recessive  characters  reappear  in  a 
certain  number  of  the  progeny  of  the  second  gen- 
eration. 

Mendel  found,  for  example,  that  if  a  pea  grown 
on  a  tall  vine  was  hybridized  with  one  grown  on 
a  short  vine,  the  progeny  of  the  first  generation 
would  all  be  tall, — tallness  of  vine  being  "  dom- 
inant. "  But  the  recessive  trait  of  shortness,  al- 
though submerged  in  the  hybrid  of  the  first  gen- 
eration, will  appear  in  one  individual  in  four  of 
the  offspring  of  the  second  generation.  It  is  obvi- 
ous that  the  fact  that  the  flowers  are  self -fertilized 
simplifies  the  experiment,  insuring  that  the  hy- 
brids shall  be  inbred,  and  preventing  the  intro- 
duction of  new  hereditary  strains  that  might  com- 
plicate the  results. 

Some  of  Mr.  Burbank's  earliest  experiments 
were  made  with  different  varieties  of  beans.  For 
example,  he  hybridized  two  varieties  of  bean, 
one  of  which  produced  a  crimson  pod  with  red 
beans  and  the  other  a  crimson-and-white-striped 
pod  with  red-and-white-striped  seed.  Curiously 
enough,  the  hybrid  beans  were  jet  black  in  color, 

[115] 


LUTHER  BURBANK 

unlike  either  parent.  But  in  the  succeeding  gen- 
eration the  offspring  of  the  black  bean  broke  up 
into  new  groups,  some  of  them  producing  black 
beans,  some  red,  some  speckled,  and  some  white. 
There  were  corresponding  variations  as  to  size 
and  shape  of  the  beans,  and  as  to  time  of 
ripening. 

Meantime  the  hybrid  vines  showed  the  enhanced 
vitality  that  is  somewhat  characteristic  of  hybrids. 
They  grew  enormously,  outstripping  their  parent 
by  eight  or  ten  feet. 

But  the  vines  of  the  second  generation  were 
extraordinarily  diversified,  some  of  them  growing 
with  great  vigor  and  others  being  dwarfed,  and 
of  such  stocky  growth  that  their  pods  trailed  the 
ground. 

In  another  experiment  Mr.  Burbank  hybrid- 
ized the  pole  bean  and  the  lima  bean,  and  the 
hybrid  showed  at  first  the  characteristics  of  both 
parents,  but  subsequently  took  on  the  form  of 
the  pole  bean.  Mr.  Burbank  notes  that  this  case 
is  somewhat  comparable  to  that  in  which  he  hy- 
bridized the  strawberry  and  the  raspberry.  In 
that  case  the  vines  were  at  first  like  the  straw- 
berry, and  then  shot  up  like  raspberry  plants. 
The  case  of  the  hybrid  beans  that  showed  both 
gigantic  and  dwarfed  progeny  in  the  second  gen- 
eration is  comparable  to  that  of  Mr.  Burbank 's 
hybrid  walnuts,  in  which  some  individuals  of  the 
second  generation  grew  ten  times  as  fast  as 
others. 

In  more  recent  years  Mr.  Burbank  has  hybrid- 
[116] 


IN  THE  VEGETABLE  GARDEN 

ized  many  varieties  of  beans,  and  has  found  it 
feasible  to  segregate  and  recombine  the  traits  of 
different  varieties  in  almost  any  desired  combina- 
tion. 

By  hybridizing  and  selection  he  has  been  able 
"to  put  the  pod  of  one  bean  on  the  vine  of  an- 
other," somewhat  as  Mendel  did  with  his  peas. 
He  has  operated  with  about  forty  varieties  of 
beans,  and  has  produced  new  combinations  almost 
infinite  in  number.  No  plant,  he  says,  can  present 
greater  surprises  or  wider  diversity  among  the 
hybrid  progeny.  And  he  thinks  that  the  bean 
offers  as  many  inducements  for  improvement  as 
any  other  plant  under  cultivation.  It  is  a  plant 
that  should  prove  peculiarly  attractive  to  the 
amateur. 

Many  varieties  of  beans  are  available,  and  they 
may  be  grown  readily  in  any  corner  of  the  vege- 
table garden.  If  you  will  hybridize  almost  any 
varieties  that  are  at  hand,  you  may  be  sure  of 
interesting  results  next  season. 

EXPERIMENTS   WITH   SWEET    COEN 

Another  plant  with  which  you  may  experiment 
with  full  assurance  of  interesting  results  is  the 
sweet  corn. 

If  you  have  chanced  to  grow  in  your  gardens  two 
varieties  of  corn,  one  having  yellow  kernels  and 
the  other  white,  you  have  probably  noticed  ears 
that  were  mixed,  bearing  partly  white  and  partly 
yellow  kernels. 

[117] 


LUTHER  BURBANK 

These  were  the  product  of  cross-breeding  ex- 
periments performed  for  you  by  the  wind. 

And  had  you  chosen  to  do  so  you  might  have 
carried  the  experiments  further  and  been  witness 
of  the  application  of  some  very  fascinating  prin- 
ciples of  heredity.  Now  that  your  attention  is 
called  to  it,  you  will  do  well  to  take  the  matter 
into  your  own  hands  and  forego  the  assistance  of 
the  wind  in  the  particular  experiments  in  question. 

The  pollen  of  the  corn,  as  you  doubtless  know, 
is  borne  in  the  tassel  at  the  top  of  the  stalk.  The 
pistillate  flowers  are  borne  on  the  stalk  itself,  and 
their  presence  is  indicated  by  the  putting  out  of 
the  familiar  wisps  of  so-called  silk,  each  strand 
of  which  is  in  reality  a  pistil  that  leads  to  the  egg 
cell,  which,  if  fertilized,  will  become  a  kernel  of 
corn. 

Under  ordinary  conditions  the  pollen  sifts 
through  the  air  and  is  dusted  over  the  silky  pistils, 
its  germinal  nucleus  making  its  way  along  the 
substance  of  the  tenuous  pistil  to  the  egg  cell.  If 
there  are  different  varieties  of  corn  growing  in 
the  same  neighborhood,  cross-fertilization  is  al- 
most certain  to  occur. 

In  the  case  of  most  kinds  of  plants,  cross- 
fertilization  does  not  affect  the  appearance  of  the 
immediate  fruit,  but  shows  its  effect  in  the  plants 
that  grow  from  the  seed. 

But  corn  is  anomalous  in  this  regard,  for  the 
kernel  shows  at  once  the  influence  of  the  foreign 
pollen. 

If,  for  example,  the  pistils  of  the  variety  of 
£118] 


IN  THE  VEGETABLE  GARDEN 

corn  that  ordinarily  bears  white  kernels  are  fer- 
tilized with  pollen  from  a  yellow  variety,  the 
kernels  will  be  yellow,  because  this  color  is  "dom- 
inant," in  the  Mendelian  sense.  And  if  part  of 
the  pistils  receives  pollen  from  the  yellow  variety 
and  part  from  the  white  variety,  the  resulting 
ear  may  be  variegated,  some  kernels  being  yellow 
and  some  white.  Thus  you  may  know  at  once 
whether  cross-pollenation  has  been  effected. 

This  obviously  gives  a  clew  to  some  interesting 
possibilities  of  experiment. 

You  might,  for  example,  apply  pollen  from  two 
or  three  different  varieties  of  corn  to  different 
parts  of  the  silky  tassel.  You  will  thus  secure 
an  ear  of  corn  that  is  a  conglomerate  of  different 
strains  of  heredity. 

There  are  other  qualities  beside  color  that  may 
be  considered.  For  example,  some  varieties  of 
corn  have  more  starch,  others  more  sugar.  The 
starchy  kernels  are  plump,  the  sugary  kernels 
wrinkled  when  mature.  Starchiness  is  dominant 
to  the  other  condition;  so  the  kernels  fertilized 
by  the  starchy  variety  will  be  plump,  in  contrast 
to  the  wrinkled  sugary  ones. 

It  is  obvious  that  interesting  combinations  are 
possible  if  you  hybridize,  let  us  say,  a  variety 
having  starchy  white  kernels  with  one  having 
sweet  yellow  ones. 

The  immediate  result  of  this  particular  com- 
bination would  be  that  all  the  kernels  of  an  ear 
thus  cross-pollenized  would  be  plump  and  yellow. 
But  if  these  kernels  are  planted,  the  crop  grown 

[119] 


LUTHER  BURBANK 

from  them  next  season  (if  self -fertilized)  will 
show  interesting  varieties  and  recombinations  of 
the  various  qualities.  There  will  be  some  kernels 
that  are  plump  and  yellow,  others  that  are  plump 
and  white;  some  that  are  wrinkled  and  yellow, 
others  that  are  wrinkled  and  white. 

And  there  is  exceptional  interest  in  the  fact 
that  these  different  types  of  kernels  may  appear 
on  the  same  ear,  and  that  they  will  exist  in  a 
predictable  mathematical  proportion.  In  accord- 
ance with  Mendelian  principles  there  will  be 
three  yellow  kernels  to  one  white,  and  three  plump 
ones  to  one  wrinkled.  But  further  breeding  ex- 
periments would  show  that  two  out  of  three  plump 
kernels  carry  the  wrinkled  condition  as  a  recessive 
trait,  and  that  two  out  of  three  of  the  yellow  ones 
carry  whiteness  as  a  recessive  trait.  This  can 
be  proved  by  planting  the  kernels  and  observing 
their  progeny  in  another  season. 

The  experiment  thus  carried  out  will  come  to 
have  the  fascination  of  a  game  of  chance,  but  un- 
like most  games  of  chance,  it  will  well  repay  the 
effort  bestowed  upon  it. 

Incidentally,  in  the  course  of  such  an  experi- 
ment, you  will  probably  be  able  to  develop  new 
varieties  of  sweet  corn  that  will  meet  with  ap- 
proval on  the  table,  at  the  same  time  that  you  are 
finding  entertainment  in  a  game  at  heredity  in 
which  you  co-operate  with  nature  and  direct  her 
forces. 


[120] 


MR.  BURBANK'S  WHITE  BLACKBERRY. 

This  remarkable  variety  was  produced  by  crossbreeding  and  selec- 
tion. It  is  now  a  thoroughly  fixed  variety,  coming  true  from  the 
seed.  If  such  a  fruit  were  found  in  a  state  of  nature  it  would  unhes- 
itatingly be  pronounced  a  distinct  species. 


IN  THE  VEGETABLE  GARDEN 

MODEKN    COEN   AND   ITS  ANCESTEY 

Mr.  Burbank  in  the  early  day  of  his  work  as 
a  gardener  devised  a  method  of  forcing  sweet  corn 
in  such  a  way  as  to  bring  it  to  market  ten  days 
or  so  in  advance  of  the  ordinary  time  of  matur- 
ing. The  method  consisted  of  generating  the  seeds 
in  the  greenhouse  and  then  planting  them  after 
they  had  formed  roots  and  sprouts  an  inch  or  more 
in  length.  No  attention  was  paid  to  the  way  in 
which  the  little  plants  fell  into  the  drills  or  fur- 
rows in  which  they  were  planted.  They  were 
simply  dropped  in  as  kernels  of  corn  would  be 
dropped,  and  covered  with  a  thin  layer  of  soil. 

Sometimes  they  continued  to  grow  so  rapidly 
that  they  would  be  found  pressing  through  the 
soil  the  next  morning;  and  this  start  caused  the 
plant  to  outstrip  others  that  were  grown  from  the 
seed  in  the  ordinary  way. 

In  recent  years  Mr.  Burbank  has  experimented 
very  extensively  with  corn,  in  particular  with  the 
primitive  type  known  as  teosinte,  a  giant  form  of 
grass  indigenous  to  Mexico.  This  plant  bears  a 
head  that  is  more  like  a  head  of  wheat  than  like 
an  ear  of  corn.  But  by  selective  breeding  and 
hybridization  Mr.  Burbank  has  been  able  to  pro- 
duce all  gradations  between  this  primitive  type 
of  corn  and  the  familiar  cultivated  varieties.  He 
has  thus  virtually  demonstrated  that  the  culti- 
vated corn  is  descended  from  teosinte. 

It  is  possible  by  selective  breeding  to  increase 
the  size  of  the  cornstalk,  and  to  cause  the  ears  to 

[121] 


LUTHER  BURBANK 

be  borne  at  any  desired  height  from  the  ground. 
Mr.  Burbank  has  developed  a  variety  of  corn,  for 
example,  that  bears  its  ears  at  such  a  height  that 
a  man  can  scarcely  reach  them.  Such  a  .variety 
has  no  commercial  value,  but  was  developed  for 
its  scientific  interest. 

You  may  amuse  yourself  by  developing  from 
the  same  stalk  a  variety  of  corn  bearing  the  ears 
at  the  height  of  five  or  six  feet  and  another  variety 
bearing  them  only  a  foot  from  the  ground.  Such 
a  series  of  experiments  has  been  carried  out  suc- 
cessfully by  the  Agricultural  Experiment  Station 
of  Minnesota.  It  is  possible  also  to  modify  the 
chemical  composition  of  the  corn,  increasing  or 
decreasing  its  protein  content. 

Such  experiments,  aside  from  their  possible 
practical  value,  have  a  high  degree  of  interest, 
and  they  fall  readily  within  the  scope  of  the 
operations  of  the  amateur  who  has  even  the  small- 
est garden  at  his  disposal. 

Another  interesting  variation  has  to  do  with 
color  of  leaf  of  the  corn  plant.  By  selective  breed- 
ing, Mr.  Burbank  has  produced  a  variety  called 
rainbow  corn  because  of  the  striping  of  the  leaves. 
He  now  contemplates  combining  this  with  sweet 
corn  of  good  quality,  so  that  the  plant  may  com- 
bine ornamental  quality  with  practical  utility. 

COMBINING   POTATO   AND   TOMATO 

Experiments  of  a  totally  different  kind  that  may 
lead  to  even  more  fascinating  results  may  be  per- 

[122] 


IN  THE  VEGETABLE  GARDEN 

formed  with  the  potato  and  the  tomato,  along  the 
lines  of  an  experiment  first  made  a  good  many 
years  ago  by  Mr.  Burbank.  This  consists  of 
grafting  the  stem  of  the  tomato  plant  on  the  roots 
of  the  potato,  and,  contrariwise,  the  stem  of  the 
potato  on  the  roots  of  the  tomato. 

The  process  of  grafting  is  not  unlike  that  of 
grafting  twigs  on  a  tree,  consisting  essentially  of 
bringing  the  cut  surfaces  of  the  two  stems  in  close 
and  accurate  contact,  and  binding  them  together 
until  union  is  effected.  The  stems  should  be  of 
the  same  size,  and  it  will  be  well  to  notch  them  in 
such  a  way  that  they  fit  accurately  together.  The 
experiment  will  not  be  successful  in  every  case, 
but  the  interesting  results  of  a  single  success  will 
compensate  for  many  failures. 

In  Mr.  Burbank 's  experiments  the  potatoes 
grown  on  vines  having  tomato  tops  were  curi- 
ously distorted  in  shape,  and  some  of  them  had  a 
rough  and  scaly  surface.  The  leaves  of  the  to- 
mato were  seemingly  not  able  to  produce  just  the 
right  kind  of  material  for  the  manufacture  of 
normal  potatoes,  yet  they  performed  their  vicari- 
ous function  better  than  might  have  been  expected, 
considering  that  under  normal  conditions  they  are 
called  on  to  produce  material  for  something  so 
widely  different  from  the  potato  as  the  familiar 
fruit  of  the  tomato. 

Perhaps  it  should  be  explained  that  the  leaf  of 
a  plant  contains  the  laboratory  in  which  carbonic 
acid  from  the  atmosphere  is  compounded  with 
water  to  form  the  organic  sugars  and  starches 

[123] 


LUTHER  BURBANK 

that  are  the  original  basis  for  the  building  of 
living  matter.  The  starch  of  the  potato  is  not 
manufactured  in  the  ground,  but  in  the  leaf  of 
the  potato  vine,  whence  it  is  transmitted  in  the 
form  of  a  soluble  sugar  to  the  root,  and  there 
transformed  into  starch  and  deposit  in  the  tuber. 

This  must  be  understood  if  one  would  appre- 
ciate the  unwonted  task  to  which  the  tomato  tops 
were  called  when  they  found  themselves  joined  to 
the  stem  of  a  potato  plant. 

When  the  combination  was  made  the  other  way, 
the  tomato  roots  proved  unable  to  develop  the 
capacity  to  form  tubers,  but  the  potato  tops  re- 
tained their  tendency  to  develop  material  for  the 
manufacture  of  tubers. 

So  a  compromise  was  effected  by  growing  the 
potato  not  underground  on  the  roots  of  the  to- 
mato, but  in  the  air,  from  the  axils  of  the  leaves 
of  the  potato  plant. 

A  potato  vine  grafted  on  tomato  roots  and 
decorated  with  aerial  potatoes  is  surely  an  anom- 
aly that  would  excite  interest  in  any  garden.  Mr. 
Burbank  has  shown  us  how  to  produce  this 
anomaly,  and  there  is  no  reason  why  the  experi- 
ment should  not  be  repeated.  It  is  true  that  no 
permanent  vegetable  of  value  has  been  developed 
in  this  way,  but  the  experiment  has  interest  that 
fully  justifies  it,  quite  aside  from  any  question  of 
practicality. 

It  is  possible,  moreover,  that  plants  thus  grafted 
might  be  more  susceptible  of  hybridization,  and 
that  a  new  and  important  vegetable  might  be  pro- 

[124] 


IN  THE  VEGETABLE  GARDEN 

duced  by  hybridizing  the  flowers  of  the  potato 
and  tomato.  Hitherto  Mr.  Burbank  has  been  un- 
able to  effect  this  hybridization,  although  he  has 
many  times  attempted  it.  But  he  is  foremost  to 
proclaim  that  such  negative  experiments  are  never 
final. 

The  case  of  the  sunberry — produced  after 
twenty-five  years  of  fruitless  effort — among 
others  taught  him  that  one  may  succeed  at  last  in 
hybridizing  two  species  that  have  refused  to  unite 
in  thousands  of  earlier  experiments.  It  is  well 
known  that  as  a  rule  plants  that  cannot  be  hy- 
bridized cannot  be  successfully  grafted.  So  the 
fact  that  potato  and  tomato  may  be  grafted  is  in 
itself  evidence  of  the  probable  feasibility  of  hy- 
bridizing the  two  under  proper  conditions. 

Any  amateur  may  raise  a  few  tomato  vines  and 
a  few  potatoes  and  the  transfer  of  pollen  from 
one  to  the  other  may  readily  be  effected.  Should 
fertilization  result,  the  hybrid  combining  the 
strains  of  the  potatb  and  tomato  is  sure  to  be  a 
plant  of  exceptional  interest,  and  not  unlikely  it 
will  prove  a  valuable  addition  to  the  list  of  garden 
vegetables.  At  all  events,  the  attempt  to  effect 
this  hybridization  is  worth  half  an  hour  of  your 
time. 

If  you  were  to  succeed  where  Mr.  Burbank  has 
failed,  your  feat  would  indeed  be  worth  recording. 
Even  though  you  fail  of  your  main  purpose,  the 
effort  will  at  least  afford  you  an  interesting  study 
in  the  anatomy  of  flowers. 

[125] 


LUTHER  BURBANK 

VAEIED   OPPORTUNITIES 

The  foregoing  instances  will  serve  to  guide  you 
in  experiments  that  may  be  applied  to  all  the  re- 
maining products  of  the  vegetable  garden. 

Whatever  the  vegetable  to  which  you  pay  atten- 
tion, you  will  discover  that  there  is  a  considerable 
range  of  variation  among  different  specimens  of 
the  same  variety.  By  selecting  for  seed  purposes 
the  specimens  that  present  in  the  fullest  measure 
the  quality  that  you  desire  to  accentuate,  you  will 
at  once  be  on  the  track  of  the  development  of  new 
and  improved  varieties. 

If  in  any  case  you  find  that  the  plants  do  not 
vary  in  the  direction  in  which  you  think  there 
might  be  improvement,  you  may  adopt  the  expedi- 
ent of  cross-pollenizing  the  flowers,  uniting  dif- 
ferent varieties  of  the  same  species  or  individuals 
of  closely  related  species. 

You  may,  for  example,  cross-fertilize  different 
varieties  of  onions,  or  you  may  hybridize  the 
onion  with  the  leek  or  the  chive. 

Mr.  Burbank  has  produced  numberless  new 
varieties  of  the  onion  family  by  hybridizing  its 
different  members.  Some  of  these  have  beautiful 
blossoms,  and  some  have  bulbs  of  extraordinary 
size.  The  Burbank  pink  chive,  for  example,  is  a 
decorative  border  flower  as  well  as  a  palatable 
table  vegetable.  And  there  are  beds  of  his  hybrid 
onions  that  take  fairly  high  rank  in  the  flower 
garden. 

Meantime  he  has  developed  varieties   of  the 
[126] 


IN  THE  VEGETABLE  GARDEN 

Spanish  onion  with  bulbs  weighing  three  or  four 
pounds. 

He  states  that  the  various  members  of  this 
family  are  easy  to  work  with  by  way  of  selection, 
and  that  the  only  difficulty  in  hybridizing  them  is 
due  to  their  small  flowers,  and  may  readily  be 
overcome  by  the  use  of  reasonable  care.  Whether 
by  hybridizing  or  by  mere  selection,  he  says,  the 
onion  is  susceptible  of  great  improvement  along 
various  lines, — size,  flavor,  decrease  of  odor, — and 
the  ease  with  which  it  may  be  cultivated  especially 
commends  it  to  the  amateur. 

In  recent  years  Mr.  Burbank  has  made  ex- 
tensive experiments  in  developing  the  artichoke,  a 
vegetable  that  is  exceedingly  popular  in  Europe, 
but  which  until  recently  has  been  somewhat  neg- 
lected in  America.  The  artichoke  is  a  composite 
flower;  that  is  to  say,  it  belongs  to  the  family  of 
which  the  sunflower  furnishes  the  type,  and  which 
is  characterized  by  growing  a  large  number  of 
flowers  in  a  single  head,  surrounded  by  a  row  of 
petal-like  rays.  In  cross-fertilizing  flowers  of  this 
type,  Mr.  Burbank  is  accustomed  to  wash  away  the 
pollen  with  a  stream  of  water  from  a  garden  hose 
before  applying  the  head  of  another  flower  and 
rubbing  the  two  flower  heads  gently  together  to 
effect  pollenization. 

The  part  of  the  artichoke  that  is  eaten  is  the 
flower  head  itself,  the  protecting  bracts  of  which 
have  developed  a  pulpy  portion  at  their  base.  The 
receptacle  on  which  the  flowers  grow,  known  as 
the  heart  of  the  artichoke,  is  also  edible.  But  the 

[127] 


LUTHER  BURBANK 

flower  must  be  plucked  before  it  opens,  as  it  is 
inedible  after  coming  to  maturity. 

By  crossing  various  varieties  of  the  European 
artichoke,  and  by  selective  breeding,  Mr.  Burbank 
has  developed  new  varieties  that  are  exceedingly 
large,  the  flower  heads  being  more  than  two  feet 
in  circumference  when  open.  The  mature  flower, 
with  its  mass  of  blue  flurries,  is  so  attractive  that 
it  is  sometimes  allowed  to  open  and  picked  for 
ornamental  purposes. 

The  artichoke  has  been  so  little  worked  with 
that  it  offers  good  opportunities  for  the  amateur, 
either  through  cross-breeding  or  merely  through 
selection.  Plants  grown  from  the  seed  are  sure 
to  show  a  certain  range  of  variation,  and  you 
may  readily  develop  improved  varieties  by  select- 
ing seeds  from  the  best  and  repeating  the  selection 
through  two  or  three  successive  generations. 

Parsley,  the  mints,  the  mustards,  cabbages, 
turnips,  peppers — all  of  these  have  been  worked 
with  extensively  by  Mr.  Burbank,  and  all  have  pos- 
sibilities of  development  that  make  them  attractive 
for  the  amateur. 

Another  vegetable  with  which  one  of  Mr.  Bur- 
bank's  greatest  triumphs  has  been  effected  is  the 
winter  rhubarb,  which  came  from  New  Zealand 
with  a  stem  scarcely  larger  than  a  lead  pencil, 
but  which  has  now  been  developed  until  it  is  of 
gigantic  size,  and  which  has  taken  on  the  habit 
of  perpetual  bearing.  The  latter  habit  is  ex- 
plained, in  part  at  least,  by  the  fact  that  the 
rhubarb  came  from  another  hemisphere.  Summer 

[128] 


IN  THE  VEGETABLE  GARDEN 

in  New  Zealand  is  of  course  our  winter  time,  and 
vice  versa,  and  the  plant  found  it  difficult  to  adjust 
itself  to  the  new  order  of  seasons.  By  encourag- 
ing it  to  maintain  its  old  system  of  reckoning  in 
the  new  latitude,  Mr.  Burbank  made  it  practically 
a  perpetual  bearer.  It  is  at  its  best  in  the  win- 
ter season,  when  ordinarily  rhubarb  is  altogether 
dormant. 

Another  important  line  of  experiment  to  which 
Mr.  Burbank  has  devoted  much  time  and  atten- 
tion has  to  do  with  the  introduction  of  new  races 
of  garden  vegetables.  He  has  worked  with  a 
species  of  lily  called  the  camassia,  which  bears 
beautiful  flowers,  until  its  bulb  gives  promise  of 
rivaling  the  potato.  He  is  similarly  educating 
another  lily  called  the  brodiaea;  and  yet  another 
known  as  the  tigridia — a  bearer  of  beautiful  flow- 
ers; and  he  has  even  turned  attention  to  such 
hitherto  unwelcome  plants  as  the  dandelion,  the 
thistle,  and  the  burdock,  all  of  which  he  believes 
are  likely  candidates  for  admission  to  the  vege- 
table garden. 

The  bulb  of  the  tigridia  is  regarded  by  Mr.  Bur- 
bank  as  the  most  delicious  of  vegetables  when 
cooked. 

Sundry  tropical  solanums — relatives  of  the  po- 
tato and  tomato — are  being  relieved  of  their 
spines  and  educated  to  bear  better  fruits  by  Mr. 
Burbank.  The  ground  cherry  and  the  passion 
flower  are  other  plants  that  he  has  in  training, 
the  fruits  of  which  have  already  made  significant 
progress.  In  the  further  development  of  these 

[129] 


LUTHER  BURBANK 

plants,  and  a  good  many  others,  any  amateur  who 
chooses  to  master  the  technique  of  plant  experi- 
mentation may  take  a  hand,  and  there  are  few 
fields  that  offer  better  opportunities  for  the  em- 
ployment of  leisure  half-hours. 

Viewed  in  this  light,  the  vegetable  garden  be- 
comes a  maze  of  fascinating  and  beckoning  mys- 
teries. 


[130] 


CHAPTEE  VII 
BURBANK  IN  THE  FLOWER  GARDEN 

THIS  chapter  describes  Mr.  Burbank's 
method  of  mating  the  flowers  with  an  eye 
to  the  production  of  new  varieties,  and  the 
methods  of  selective  breeding  through  which  the 
colors  and  forms  of  blossoms  may  be  developed. 

Almost  any  flower  may  be  improved  in  size, 
changed  in  form,  made  double,  or  altered  in  color. 
Mr.  Burbank  has  made  hundreds  of  such  modifica- 
tions in  the  case  of  flowers  from  all  parts  of  the 
world,  including  both  the  common  garden  varie- 
ties and  the  rarest  exotics. 

The  exact  method  by  which  these  changes  are 
wrought  is  here  described, — how,  for  example,  the 
Shasta  daisy  was  developed,  the  scented  calla, 
the  blue  poppy,  the  crimson  eschscholtzia,  and 
numerous  others.  Typical  illustrations  are  given 
as  to  each  of  the  different  methods  of  procedure, 
and  the  entire  process  is  so  clearly  described  that 
the  amateur  may  produce  similar  results  if  he 
will  intelligently  follow  the  directions  given. 

You  may  have  flowers  different  from  those  of 
your  neighbor,  and,  indeed,  different  from  any 
that  have  ever  been  seen  before,  if  you  are  willing 
to  take  the  trouble  to  develop  them.  And  it  will 
appear  that  in  many  cases  new  developments  may 

[131] 


LUTHER  BURBANK 

be  brought  forth  rapidly.  In  dealing  with  flowers, 
you  are  not  required  to  wait  for  a  term  of  years, 
as  you  sometimes  would  be  in  developing  new 
races  of  orchard  fruits.  For  this  reason,  and  also 
because  of  the  great  variety  of  interests  that  at- 
tach to  flowers,  the  amateur  may  very  well  begin 
his  experiments  in  the  flower  garden. 

In  undertaking  the  improvement  of  a  flower, 
one  may  have  in  mind  the  form  of  the  blossom, 
its  size,  profusion  of  bearing,  color,  or  odor.  Mr. 
Burbank 's  work  furnishes  almost  countless  illus- 
trations of  improvement  in  regard  to  all  of  these 
qualities,  sometimes  singly,  sometimes  in  com- 
bination. 

Of  course  the  simplest  type  of  experiment  is 
that  in  which  a  single  quality  is  under  considera- 
tion. Such  a  case  as  that  of  Mr.  Burbank's 
scented  calla  furnishes  a  typical  illustration. 

The  calla,  as  everyone  knows,  is  ordinarily  quite 
without  a  pleasing  fragrance;  if  it  has  any  odor 
at  all  it  is  a  slightly  disagreeable  one.  But  the 
variety  of  calla  developed  by  Mr.  Burbank  and 
introduced  under  the  name  of  Fragrance  has  a 
delicious  perfume  that  adds  very  greatly  to  the 
attractiveness  of  this  beautiful  flower,  and  Mr. 
Burbank  tells  us  that  this  quality  of  fragrance 
was  developed  in  the  calla  in  the  course  of  three 
generations  of  selective  breeding,  without  hy- 
bridization. 


[132] 


IN  THE  FLOWER  GARDEN 

WHY   FLOWEES   HAVE   PEKFUME 

Most  readers  are  probably  aware  that — accord- 
ing to  accepted  theory — the  perfume  of  flowers  in 
general  has  been  developed  through  natural  se- 
lection as  an  aid  in  attracting  insects,  on  which 
the  plant  depends  for  cross-fertilization.  We 
human  beings  have  come  to  enjoy  the  fragrance  of 
the  rose  and  the  apple  blossom,  and  we  are  some- 
times egotistical  enough  to  suppose  that  these 
perfumes  were  developed  for  our  delectation. 

But  the  botanist  assures  us  that,  so  far  as  the 
wild  flowers  are  concerned,  man's  tastes  were  not 
in  the  least  consulted  in  the  development  of  either 
color  or  fragrance. 

The  development  of  scented  and  beautiful  flow- 
ers was  the  work  of  sundry  insects,  of  which  the 
bee  is  most  important.  The  colored  petals  of  the 
flower  and  the  perfume  that  it  exhales  are  adver- 
tisements addressed  to  the  bee,  intended  to  guide 
him  to  the  nectary  within  the  tube  of  the  flower, 
in  approaching  which  the  insect  will  unconsciously 
come  in  contact  with  the  pollen-bearing  stamens, 
and  in  due  course  transfer  the  pollen  from  one 
flower  to  another. 

When,  therefore,  we  find  a  flower  like  the  calla 
that  is  devoid  of  fragrance,  we  may  feel  pretty 
certain  that  this  flower  is  not  habitually  fertilized 
by  the  bee,  but  depends  upon  some  other  agency. 

In  the  case  of  the  calla,  the  agents  that  effect 
cross-fertilization  are  sundry  small  gnats  and 
flies  that  find  the  tubular  canopy  a  welcome  shelter 

[133] 


LUTHER  BURBANK 

at  night.  This  white  canopy  is  really  a  modified 
leaf  and  is  called  by  the  botanist  a  spathe.  The 
essential  organs  of  the  flower  are  distributed  on 
the  central  column  called  a  spadix,  and  are  ex- 
ceedingly inconspicuous.  The  upper  portion  of 
the  spadix  bears  the  pollen,  and  the  lower  portion 
is  the  pistillate  surface.  But  the  two  parts  do 
not  mature  at  the  same  time,  so  self-fertilization 
does  not  take  place  as  would  otherwise  be  in- 
evitable. 

It  has  been  found  by  experiment  that  the  air 
inside  the  tubular  spathe  is  somewhat  warmer 
than  the  outside  air.  So  it  is  not  strange  that 
insects  should  gather  here,  and  they  naturally 
come  in  contact  with  the  pollen,  and  carry  it  to 
other  flowers  that  they  subsequently  visit.  The 
whiteness  of  the  calla  suggests  that  it  is  designed 
to  attract  night-roving  insects,  the  white  flower 
being  more  conspicuous  at  night  than  a  brightly 
colored  one. 

MAKING  A   FBAGEANT   CALLA 

It  is  not  unlikely  that  some  ancestors  of  the 
calla  depended  on  the  bee  for  cross-fertilization, 
and  hence  were  fragrant.  Otherwise  it  is  hard 
to  account  for  the  appearance  in  Mr.  Burbank's 
colony  of  callas  of  an  individual  that  had  a  faint 
but  appreciable  perfume. 

Whatever  the  explanation,  such  an  anomaly  did 
appear  a  good  many  years  ago,  and  Mr.  Burbank 
detected  its  presence  and  at  once  decided  that  this 

[  134  ] 


IN  THE  FLOWER  GARDEN 

flower  was  worthy  of  cultivation.  He  carefully 
saved  the  seed  of  this  individual,  and  watched  the 
development  of  the  progeny  with  solicitude.  Most 
of  them  were  quite  odorless.  But  there  were  a 
few  that  reproduced  the  fragrance  of  their  parent, 
and  one  of  these  was  more  distinctly  fragrant  than 
the  original. 

The  seeds  of  this  specimen  were  saved  in  turn, 
and  among  the  plants  that  grew  from  them  were 
several  that  were  distinctly  fragrant,  and,  as  be- 
fore, one  that  conspicuously  excelled  the  others. 
Indeed,  the  perfume  had  now  been  so  accentuated 
that  this  individual  was  as  fragrant  as  could  be 
desired.  The  plant  was  propagated  by  dividing 
the  roots,  after  the  usual  method,  and  soon  a  com- 
pany of  callas  was  produced,  all  of  which  dupli- 
cated the  qualities  of  the  parent  form.  This  was 
the  flower  that  was  sent  out  under  the  name  of 
Fragrance. 

The  process  of  development  of  the  scented  calla, 
then,  consisted  in  raising  seedlings  from  an  indi- 
vidual that  showed  a  trace  of  perfume  and  select- 
ing in  turn  through  successive  generations  the 
individual  that  had  inherited  this  quality  in 
largest  measure. 

But  the  most  interesting  feature  of  the  experi- 
ment was  the  fact  that  the  quality,  although  not 
transmitted  to  most  of  the  progeny,  was  accentu- 
ated in  the  case  of  the  individual  to  which  it  was 
transmitted. 

And  this,  fortunately,  is  typical.  Wherever  a 
flower  shows  a  peculiarity  that  differentiates  it 

[135] 


LUTHER  BURBANK 

from  its  fellows,  this  peculiarity  may  be  accentu- 
ated or  exaggerated  by  selective  breeding.  And 
sometimes  the  development  is  gratifyingly  rapid. 

NEW   COLOES   IN   THE   POPPY 

As  another  illustration  of  this,  take  the  case  of 
Mr.  Burbank's  crimson  California  poppy,  named 
by  the  botanist  Eschscholtzia. 

This  flower  in  its  wild  state  is  of  a  brilliant 
orange  color,  but  one  day  Mr.  Burbank  discovered 
a  specimen  that  showed  a  thin  line  of  crimson  run- 
ning up  the  center  of  one  petal.  The  seeds  of  this 
poppy  were  carefully  preserved,  and  among  the 
plants  that  grew  from  them  one  was  discovered 
that  had  a  flower  with  a  slightly  wider  line  of 
crimson. 

The  next  generation  showed  farther  progress 
in  the  same  direction,  and  presently  a  poppy  had 
been  produced  the  petals  of  which  were  crimson 
throughout. 

There  was  no  necessity  for  hybridization  or 
for?  any  directive  manipulation.  All  that  was 
necessary  was  to  preserve  and  sow  the  seed  of  the 
plant  that  showed  the  tendency  to  vary,  and  thus 
to  give  the  new  color  an  opportunity  to  assert 
itself. 

In  this  case  the  crimson  color  appeared,  as  just 
related,  as  a  narrow  but  conspicuous  line.  There 
are  other  cases  in  which  a  new  color  appears  only 
as  a  modified  tone,  readily  overlooked  by  the 
casual  observer.  Such  a  case  was  that  of  the 

[136] 


INSPECTING   HYBRID  BLACKBERRIES 

Mr.  Burbank  (at  the  right)  is  discussing  with  Dr.  Williams  the  results  of 
an  experiment  in  crossing  the  thornless  blackberry  with  various  other  selected 
varieties. 


IN  THE  FLOWER  GARDEN 

flower  from  which  Mr.  Burbank  developed  his 
celebrated  blue  poppy. 

The  flower  that  showed  the  original  tendency  to 
variation  was  a  Shirley  poppy,  the  red  color  of 
which  lacked  a  little  of  its  usual  beauty.  To  Mr. 
Burbank 's  discerning  eye  there  seemed  a  certain 
smokiness  of  hue  that  suggested  possibilities  of 
variation.  So  of  course  the  seeds  of  this  poppy 
were  carefully  preserved.  In  the  next  generation 
there  were  a  few  individuals  that  showed  a  more 
conspicuous  smokiness  of  color ;  and  in  the  course 
of  three  or  four  more  generations  individuals 
appeared  that  had  flowers  distinctly  bluish  in  hue. 
This  bluish  quality  was  further  accentuated  in 
succeeding  generations,  until  a  poppy  appeared 
that  was  of  a  clear  pale-blue  color. 

There  is  no  record  that  anyone  ever  saw  a  pure 
blue  poppy  before,  yet  the  materials  for  blue  pig- 
mentation were  evidently  hidden  in  the  germ- 
plasm  of  the  poppy,  and  selective  breeding  re- 
moved the  obscuring  elements  and  enabled  the 
blue  color  to  make  itself  manifest.  The  principles 
of  selective  breeding  employed  were  simple  to  the 
last  degree ;  yet  through  their  application  a  flower 
was  produced  that  is  marvelously  transformed. 

Another  curious  and  interesting  color  modifi- 
cation was  effected  in  Mr.  Burbank 's  ^silver- 
lining"  poppy.  The  original  flower  was  crimson 
with  a  black  center.  A  specimen  appeared  that 
showed  a  white  line  between  the  black  center  and 
the  crimson  petal.  By  selective  breeding  this  line 
was  widened  generation  after  generation,  until 

[137] 


LUTHER  BURBANK 

the  flower  was  white  with  black  center ;  the  white 
extending  just  over  the  outer  edge  of  the  poppy, 
the  rest  of  the  backs  of  the  petals  remaining 
crimson. 

CHANGING  A  LEAP 

It  is  not  the'  blossom  alone  that  may  thus  be 
modified  by  selective  breeding.  Other  parts  of 
the  plant  may  be  similarly  transformed.  A  strik- 
ing illustration  of  this  is  furnished  by  a  leaf 
modification  that  Mr.  Burbank  brought  about  in 
the  case  of  the  California  plant  sometimes  called 
"wild  geranium,"  known  to  the  botanist  as 
heuchera. 

This  plant  usually  has  a  fairly  smooth  leaf 
with  an  indented  edge,  not  unlike  that  of  the 
ordinary  cultivated  geranium.  But  Mr.  Burbank 
once  chanced  upon  a  specimen  growing  wild  that 
showed  a  tendency  to  crinkling  of  the  edge  of  the 
leaf. 

He  transferred  this  plant  to  his  garden,  saved 
its  seed,  and  searched  among  the  progeny  for  an 
individual  that  reproduced  the  anomaly  of  leaf 
formation.  As  expected,  some  individuals  were 
found  that  not  only  reproduced  but  accentuated 
the  anomaly.  And  in  succeeding  generations  in- 
dividuals appeared  in  which  the  peculiarity  was 
so  accentuated  that  ultimately  the  leaf  became 
crinkled  and  crenated  over  practically  its  entire 
surface,  losing  all  resemblance  to  the  normal  form 
and  appearance. 

The  plant  that  showed  this  peculiarity  resem- 
[138] 


IN  THE  FLOWER  GARDEN 

bled  the  wild  parent  form  as  to  blossom  and  gen- 
eral habit.  But  its  leaves  were  so  modified  as  to 
constitute  a  new  variety  to  which  a  specific  name 
has  been  given. 

Hundreds  of  other  instances  might  be  cited  in 
which  Mr.  Burbank  has  modified  the  quality  of 
stem  or  leaf  or  flower  of  a  familiar  or  unfamiliar 
plant  by  this  process  of  selective  breeding,  in 
which  a  "  spontaneous  "  tendency  to  variation  sup- 
plied the  material  with  which  the  experimenter 
worked.  It  is  rare  indeed  for  a  plant  to  come 
under  his  observation  in  which  he  does  not  detect 
some  indication  of  what  to  his  keen  perception 
seems  a  bid  for  improvement. 

If  you  will  carefully  examine  any  group  of 
flowers  in  your  garden,  you  will  at  once  see  that 
no  two  plants  of  the  same  variety  are  precisely 
alike ;  and  if  you  wish  to  accentuate  any  observed 
variation,  you  may  undertake  the  task  with  full 
confidence,  if  you  will  follow  out  the  method  just 
outlined.  In  some  cases  progress  will  be  rapid, 
in  others  slow,  but  you  are  almost  certain  to  see 
some  improvement  among  the  progeny  of  the  first 
generation,  and  not  unfrequently  you  may  detect 
a  very  marked  transformation  in  size  or  form  or 
color,  or  in  any  other  quality  for  which  you  are 
selecting,  in  the  course  of  two  or  three  genera- 
tions. 

The  fact  appears  to  be  that  every  individual 
plant  is  the  center  of  many  conflicting  hereditary 
currents.  Selective  breeding  singles  out  a  tend- 
ency and  gives  it  an  opportunity  to  manifest  its 

[139] 


LUTHER  BURBANK 

possibilities.  By  this  method  alone  you  may  de- 
velop any  number  of  new  varieties  of  flowers  in 
your  garden  with  an  insignificant  expenditure  of 
time  and  effort. 

All  that  is  necessary  is  clearly  to  grasp  the 
principle  of  selective  breeding,  and  to  search  dili- 
gently in  each  successive  generation  for  the  indi- 
vidual that  shows  the  strongest  tendency  to  vary 
in  the  desired  direction. 

CONSTEUCTING  A   NEW   SPECIES 

But  while  remarkable  transformations  may 
thus  be  effected  by  mere  selective  breeding,  it  will 
be  understood,  of  course,  that  with  the  flowering 
plants,  as  with  fruits  and  vegetables,  it  may  often 
be  desirable  to  give  an  added  stimulus  to  varia- 
tion through  the  hybridizing  of  different  species, 
or  the  crossing  of  marked  varieties.  Indeed,  this 
is  the  usual  method  through  which  striking  new 
varieties  have  all  along  been  developed  in  Mr. 
Burbank's  garden.  Even  where  selective  breed- 
ing, along  the  lines  thus  described,  is  used  to  ac- 
centuate or  fix  a  variation,  there  has  very  com- 
monly been  a  preliminary  series  of  experiments 
in  which  variation  has  been  stimulated  through 
hybridization. 

Mr.  Burbank  early  discovered  that  new  varie- 
ties may  be  produced  by  this  method,  and  the  per- 
sistent application  of  the  method  to  countless 
species  of  plants  laid  the  foundation  for  his  con- 
spicuous successes.  Beautiful  ixias,  for  example, 

[140] 


IN  THE  FLOWER  GARDEN 

were  thus  developed,  and  marvelous  hollyhocks; 
also  new  races  of  tritonias,  and  numberless  new 
and  extraordinary  varieties  of  starflowers,  lilies, 
watsonias,  petunias,  larkspurs,  marigolds,  sun- 
flowers, and  scores  of  others. 

As  a  typical  illustration  of  what  he  has  been 
able  to  accomplish  in  this  field,  we  may  cite  the 
case  of  the  Shasta  daisy. 

This  remarkable  flower  has  for  one  of  its  an- 
cestors the  little  ox-eye  daisy  familiar  everywhere 
throughout  the  eastern  United  States.  This 
flower  was  hybridized  with  the  European  daisy, 
the  strains  of  two  subspecies  or  marked  varieties 
being  introduced.  Selective  breeding  among  these 
hybrids  produced  a  flower  that  was  much  larger 
than  either  of  the  parent  forms  and  in  many  ways 
more  graceful  and  beautiful. 

But  the  flower  was  not  of  as  pure  a  white  as 
Mr.  Burbank  desired,  and  to  improve  it  in  this 
regard,  as  well  as  to  give  it  fresh  tendency  to 
variation,  he  crossed  the  hybrid  form  with  a 
Japanese  daisy  that  had  a  small  flower  of  dazzling 
whiteness.  The  progeny  showed  the  expected 
tendency  to  variation,  and  some  of  them  combined 
the  whiteness  of  the  Japanese  parent  with  the 
large  size  and  attractive  qualities  of  the 
American-European  hybrid.  By  selective  breed- 
ing numerous  new  types  were  developed,  some  of 
them  bearing  flowers  not  far  from  six  inches  in 
diameter. 

The  new  flower  that  thus  combined  the  racial 
strains  of  three  species  was  itself  so  different 

[141] 


LUTHER  BURBANK 

from  any  one  of  the  parent  forms  that  it  would 
be  regarded  by  any  botanist  who  found  it  in  the 
wild  state  as  a  unique  species.  It  is,  in  short,  a 
new  species  of  daisy  created  by  artificial  selection 
under  the  hand  of  the  plant  developer.  It  was 
named  the  Shasta  daisy. 

Various  series  of  experiments  in  selective 
breeding  have  developed  numerous  varieties  of 
Shastas,  some  having  broad  flat  ray  flowers, 
others  thin  and  fimbriated  or  tubular  ones,  yet 
others  being  partially  double.  In  a  word,  the 
Shasta  daisy  is  not  only  a  new  form  of  flower, 
but  one  that  has  developed  numberless  varieties, 
comparable,  therefore,  with  various  other  types 
of  cultivated  flowers.  Yet  there  was  no  such  thing 
as  a  Shasta  daisy  in  existence  until  Mr.  Burbank 
combined  the  different  species  from  Europe, 
America,  and  Japan,  and  thus  gave  opportunity 
for  the  blending  of  hereditary  factors  that  had 
their  origin  in  the  environing  conditions  of  three 
continents. 

The  case  of  the  Shasta  daisy,  then,  may  be 
taken  as  typifying  the  second  of  the  two  impor- 
tant methods  through  which  the  plant  developer 
operates, — the  method  of  hybridization. 

Of  course  the  perfected  Shasta  represents  also 
the  use  of  the  other  method,  that  of  selective 
breeding.  Indeed,  the  two  methods  go  hand  in 
hand,  each  supplementing  the  other.  Taken  to- 
gether, they  constitute  the  basis  of  a  complete 
method  of  plant  development,  and  through  their 
application  all  the  possible  transformations  that 

[142] 


IN  THE  FLOWER  GARDEN 

may  be  brought  about  in  a  limited  period  of  time 
may  be  effected. 

QUANTITY   PRODUCTION 

Of  course  your  task  will  be  facilitated  if  you 
raise  large  numbers  of  individual  plants.  Part 
of  Mr.  Burbank's  phenomenal  success  is  due  to 
the  scale  on  which  he  operates.  He  raises  indi- 
viduals of  a  given  variety  not  merely  by  thou- 
sands, but  by  hundreds  of  thousands  or  millions. 
Nor  is  a  large  territory  required  for  these  opera- 
tions, particularly  in  the  case  of  flowering  plants, 
because  great  numbers  of  these  can  be  raised  in 
a  plot  a  few  feet  square,  and  only  the  most  satis- 
factory specimens  are  preserved  in  each  succeed- 
ing generation. 

As  an  instance  of  the  rigorous  selection  through 
which  Mr.  Burbank's  flowers  are  improved,  it  may 
be  related  that  on  one  occasion  he  destroyed  eight 
cords  of  bulbs  of  the  South  African  plant  called 
the  watsonia,  preserving  only  a  few  specimens 
that  were  the  superlative  ones  among  the  hun- 
dreds of  thousands. 

It  may  be  asked  why  Mr.  Burbank  destroys 
these  bulbs,  when  he  might  readily  sell  them. 

The  answer  is  that  the  bulbs  represent  an  inter- 
mediate stage  of  development,  and  as  has  been 
pointed  out  in  another  connection,  if  they  were 
allowed  to  go  out  they  would  be  advertised 
presently  by  some  unscrupulous  person  in  a  way 
to  mislead  the  public  and  do  injustice  to  the 

[143] 


LUTHER  BURBANK 

plant  developer  himself.  Mr.  Burbank  never 
allows  a  new  plant  creation  of  any  kind  to  be  in- 
troduced unless  lie  is  thoroughly  convinced  that 
it  is  equal  in  all  respects  to  any  similar  variety 
already  on  the  market,  and  superior  in  at  least 
one  respect.  Until  the  new  variety  can  meet  this 
test,  it  is  still  in  the  experimental  stage,  and  only 
a  few  of  the  most  promising  specimens  are  pre- 
served, the  others  being  ruthlessly  sent  to  the 
bonfire. 

To  the  observer  who  sees  hundreds  of  thousands 
of  the  plants  bearing  really  beautiful  flowers  thus 
destroyed  each  year  at  Santa  Rosa  and  Sebas- 
topol  the  method  seems  ruthless;  but  it  is  an 
inevitable  concomitant  of  the  comprehensive  plan 
through  which  so  many  wonderful  varieties  of 
flowers,  vegetables,  and  fruits  have  been  devel- 
oped in  Mr.  Burbank  ?s  experiment  gardens. 

Among  the  most  interesting  of  the  plant  colonies 
that  have  been  produced  in  countless  galaxies  to 
supply  Mr.  Burbank  with  material  for  selection 
are  such  familiar  flowers  as  the  lilies  and  poppies. 

HALF   A   MILLION    NEW   LILIES 

Mr.  Burbank 's  experiments  with  lilies  were  car- 
ried out  on  a  most  comprehensive  scale  for  many 
years.  He  hybridized  all  the  exotic  species  and 
varieties  that  seemed  to  promise  favorable  results, 
until  he  had  the  most  extraordinary  collection  of 
lilies,  doubtless,  that  ever  existed  anywhere  in  the 
world, — "here  a  plant  six  feet  high  with  yellow 

[144] 


IN  THE  FLOWER  GARDEN 

flowers  beside  one  only  six  inches  high  with  dark 
red  flowers,  and  farther  on  one  of  pale  straw  or 
snowy  white  or  with  curious  dots  and  shadings; 
some  deliciously  fragrant,  others  faintly  so ;  some 
with  upright,  others  with  nodding  flowers;  some 
with  dark-green  woolly  leaves  or  whorls  or  with 
polished,  light-green,  lance-like  scattered  leaves." 

In  one  of  his  early  announcements,  Mr.  Bur- 
bank  spoke  of  having  "half  a  million  kinds  of 
lilies  yet  to  unfold  their  petals  for  the  first  time," 
adding  that  he  was  still  planting  from  one  to 
three  pounds  of  hybridized  lily  seed  every  season. 

"Search  this  earth  all  over,"  he  said,  "climb 
every  mountain,  plunge  into  every  canon,  valley, 
and  jungle ;  and,  when  all  this  is  done,  visit  every 
park,  garden,  nursery,  and  conservatory ;  go  any- 
where, everywhere,  and  as  many  varieties  of 
charming  lilies  cannot  be  found  as  I  have  pro- 
duced. All  the  earth  is  not  adorned  with  so  many 
new  ones  as  are  growing  at  my  establishment." 

It  was  pointed  out  that  these  hybrid  lilies  were 
crosses  of  parents  selected  for  health,  hardiness, 
easy  management,  and  rapid  multiplication,  as 
well  as  for  fragrance,  beauty  of  coloring,  grace, 
and  abundance  of  flowers;  and  the  justifiable  as- 
sertion was  made  that  "in  these  hybrids  a  broad 
foundation  has  been  laid  for  endless  varieties 
which  will  reward  lovers  of  flowers  for  ages  to 
come." 

A  glance  at  the  photographic  reproductions  that 
accompanied  the  announcement  justified  the  plant 
developer's  enthusiasm. 

[145] 


LUTHER  BURBANK 

STBANGE   HYBEID  POPPIES 

As  to  the  poppies,  the  results  of  hybridizing 
in  Mr.  Burbank's  hands  have  been  no  less  ex- 
traordinary. Some  of  his  most  interesting  results 
have  attended  the  crossing  of  the  opium  poppy 
with  sundry  varieties  of  the  Oriental  poppy. 
Rather  curiously  he  found  that  the  pollen  of  the 
opium  poppy  was  ineffective  when  used  on  the 
Oriental,  yet  when  the  reciprocal  cross  was  made, 
the  pollen  of  the  Oriental  being  used  on  the  opium 
poppy,  seed  was  produced,  and  a  great  number  of 
hybrids  were  soon  under  observation. 

The  hybrid  colony  comprised  more  than  thirty 
thousand  plants,  including  many  extraordinary 
forms.  For  example,  the  hybrid  poppies  some- 
times produced  enormous  seed  capsules,  five  or 
six  times  as  large  as  the  ordinary  seed  capsule 
of  either  parent.  Yet  in  other  plants  the  seed 
capsule  would  be  small ;  in  still  others  twin  cap- 
sules were  produced;  and  with  numerous  others 
there  was  not  even  the  intimation  of  a  capsule, 
the  flowering  stem  ending  abruptly  like  the  end 
of  a  lead  pencil.  And  even  where  the  capsule  was 
large,  the  seeds  were  produced  in  much  dimin- 
ished quantity,  and  were  shriveled  and  shrunken 
in  size. 

The  plants  grown  from  these  seeds — second- 
generation  hybrids — were  extraordinarily  vari- 
able. Mr.  Burbank  declares  that  he  has  seldom 
seen  a  more  remarkable  company  of  plants. 
"The  diversity  was  so  great  that  it  might  be  said 

[146] 


IN  THE  FLOWER  GARDEN 

there  were  no  two  plants  among  the  thousands 
that  were  even  approximately  identical." 

The  foliage  in  particular  was  amazingly  varied. 
There  were  long,  smooth,  strap-shaped  leaves,  and 
short  stubby  ones;  smooth,  glossy  leaves,  and 
rough,  hairy  ones;  leaves  like  those  of  one  or 
the  other  of  the  parent  forms;  and  nondescript 
leaves  that  variously  suggested  the  primrose, 
cherry,  dock,  wormwood,  dandelion,  and  scores  of 
others. 

The  blossoms  were  not  only  diversified  in  color, 
and  some  of  them  enormously  increased  in  size, 
but  they  showed  a  curious  modification,  in  that 
they  were  produced  at  all  seasons  instead  of  only 
for  a  short  period,  as  is  the  habit  with  the  parent 
species. 

The  first-generation  hybrids  themselves  were 
perennial  plants  (although  their  mother  plant  was 
an  annual),  and  they  bloomed  persistently. 
"  There  is  not  a  day  in  the  year  when  some  of 
these  hybrids  are  not  in  bloom  at  Sebastopol, 
spring,  summer,  autumn,  or  winter — blossoms  can 
always  be  gathered  in  quantity  from  them. ' ' 

It  is  of  peculiar  interest  to  note  that  the  second- 
generation  hybrids  were  in  part  annuals,  like  one 
of  their  grandparents,  and  in  part  perennials,  like 
the  other  grandparent.  The  annual  and  perennial 
habit  appear  to  be  a  pair  of  Mendelian  unit  char- 
acters of  which  the  perennial  habit  was  "dom- 
inant" and  the  annual  habit  "recessive";  there 
being  a  characteristic  segregation  in  the  second 
generation. 

[147] 


LUTHER  BURBANK 

The  possibility  of  producing  almost  endless 
numbers  of  new  varieties  of  poppies  from  such  a 
conglomerate  company  is  obvious.  The  difficulties 
are  greater  than  might  appear,  however,  because 
of  the  tendency  to  sterility.  Many  hybrids  show 
greatly  increased  fecundity,  but  with  these  pop- 
pies this  is  reversed,  the  reason  being,  perhaps, 
that  the  plants  are  almost  at  the  limits  of  affinity, 
beyond  which  cross-fertilization  would  be  im- 
possible. 

THE  OKIGIN  OF  SPECIES 

It  should  be  understood  that  hybridization  and 
selection  are  natural  methods,  and  that  in  using 
them  man  is  merely  imitating  on  a  small  scale  the 
practice  by  which  nature  has  brought  about  the 
evolution  of  all  the  existing  forms  of  plant  and 
animal  life.  Plants  in  the  state  of  nature  are 
frequently  hybridized  through  the  agency  of  in- 
sects, or  by  the  wind  in  the  case  of  those  who  do 
not  depend  upon  insects  for  cross-pollenation. 

Mr.  Burbank  cites  numerous  instances  of  nat- 
ural hybrids  that  he  has  observed;  for  example, 
the  madia  plant,  or  tarweed,  two  species  of  which 
frequently  hybridize;  mints  of  various  species; 
the  wild  raspberry;  and  the  different  species  of 
hickory  nut. 

He  believes  that  such  natural  hybrids  afford  the 
material  from  which  new  species  are  constantly 
being  developed  through  natural  selection,  and  the 
results  achieved  by  Mr.  Burbank  himself  in  the 

[148] 


IN  THE  FLOWER  GARDEN 

development  of  new  species  by  this  method  go  far 
to  substantiate  his  belief.  He  habitually  hybrid- 
izes species,  and  develops  new  races  by  artificial 
selection. 

About  the  only  difference  between  this  method 
and  nature's  method  is  that  in  the  wild  state  the 
characteristics  that  are  likely  to  be  preserved 
through  natural  selection  are  those  that  are  ad- 
vantageous to  the  individual  plant  that  manifests 
them;  whereas  under  conditions  of  artificial  se- 
lection the  plant  developer  considers  not  the  needs 
of  the  individual  plant,  but  the  tastes  and  needs  of 
men. 

Perfume  is  developed  in  Mr.  Burbank's  calla, 
for  example,  and  in  his  fragrant  petunias  and 
verbenas,  not  because  this  is  of  advantage  to  the 
plants  themselves,  but  because  the  perfume  is 
pleasing  to  human  nostrils.  Similarly  the  blue 
color  of  the  poppy  is  to  please  the  human  eye,  the 
crinkled  leaf  of  the  geranium  to  satisfy  a  human 
taste  for  the  bizarre,  and  the  varied  forms  of  the 
Shasta  daisy  to  gratify  esthetic  human  sensi- 
bilities. 

Natural  selection  would  have  eliminated  rather 
than  preserved  the  variations  in  question ;  but  civ- 
ilized man  creates  a  new  environment  and  molds 
the  forms  of  vegetable  and  animal  life  to  fit  that 
environment.  The  results  are  different  because 
the  conditions  are  different.  But  the  principles 
of  development  are  the  same,  and  it  may  fairly  be 
said  that  the  plant  developer  in  applying  the 
method  of  hybridization  and  artificial  selection  is 

[149] 


LUTHER  BURBANK 

duplicating  nature's  method,  and  illustrating  on 
a  small  scale  the  principles  of  evolution  through 
which  all  living  organisms  have  been  developed. 

In  making  practical  application  of  these  meth- 
ods in  the  flower  garden,  you  may  select  whatever 
plants  are  found  there,  almost  at  random.  There 
is  no  race  of  cultivated  flowers  that  does  not  offer 
opportunities  for  improvement  through  hybridiza- 
tion and  selection.  Of  course  you  must  work,  in 
any  given  experiment,  with  species  that  are  not 
too  widely  separated;  otherwise  your  efforts  at 
hybridization  will  be  futile.  You  cannot  hope, 
for  example,  to  hybridize  a  rose  and  a  dahlia. 
But  you  may  hybridize  the  different  species  of 
roses  among  themselves  or  one  dahlia  with  an- 
other, and  in  either  case  you  will  be  fairly  certain 
to  produce  forms  that  are  different  in  some  regard 
from  the  parent  forms,  offering  opportunity  for 
further  improvement  by  selection. 

But  although,  as  a  rule,  plants  cannot  be  hy- 
bridized unless  somewhat  closely  related,  experi- 
ment may  reveal  unexpected  affinities,  even  be- 
tween species  belonging  to  different  genera.  Mr. 
Burbank  has  made  a  large  number  of  very  wide 
crosses,  some  of  which  have  already  been  referred 
to.  The  interesting  hybrid  between  the  tobacco 
and  the  petunia  may  be  recalled  as  an  instance  in 
point. 

The  curious  plants  that  resulted  from  this  union 
were  some  of  them  of  upright  growth  like  the  to- 
bacco, others  of  trailing  habit  like  the  petunia. 
It  was  said  of  them  facetiously  that  they  were 

[150] 


IN  THE  FLOWER  GARDEN 

petunias  that  had  acquired  the  tobacco  habit.  Un- 
fortunately they  seemed  incapable  of  forming  a 
good  root  system  and  hence  they  lacked  vitality. 
Mr.  Burbank  has  since  regretted  that  he  did  not 
graft  them  on  tobacco  roots,  as  in  that  way  they 
might  perhaps  have  been  preserved. 

It  would  be  well  worth  while  for  someone  to  try 
the  experiment  over  again,  carrying  out  this  sug- 
gestion. 

/  ^\ 

PRODUCING  AND  FIXING   NEW   VARIETIES 

It  will  be  recalled  that  Darwin  based  his  cele- 
brated hypothesis  of  natural  selection  on  the  ob- 
served fact  that  plants  and  animals  in  a  state  of 
nature  vary.  He  spoke  of  this  variation  as 
"spontaneous,"  thereby  confessedly  begging  the 
question.  Mr.  Burbank  believes  that  in  a  large 
number  of  cases  such  "spontaneous"  variation  is 
in  reality  due  to  hybridization.  In  the  same  way 
he  explains  the  occurrence  of  those  variations 
which,  because  of  their  wide  departure  from  the 
parent  form,  have  been  described  as  "mutants." 

The  case  of  the  mutants  was  brought  prom- 
inently to  the  attention  of  the  biological  world  a 
few  years  ago  by  Professor  Hugo  De  Vries,  the 
celebrated  Amsterdam  botanist.  His  observations 
were  chiefly  made  with  the  evening  primrose,  and 
he  founded  on  these  observations  the  theory  of 
evolution  by  mutation, — that  is,  by  sudden  vaults, 
— as  a  modification  of  the  theory  of  evolution  by 
the  accumulation  of  minute  changes. 

[151] 


LUTHER  BURBANK 

Professor  De  Vries  was  unable  to  explain  the 
cause  of  the  mutation;  but  Mr.  Burbank  at  once 
declared  his  belief  that  the  celebrated  evening 
primrose  with  which  Professor  De  Vries  had 
worked  was  really  a  hybrid,  and  this  explanation 
is  now  coming  to  be  pretty  generally  accepted. 

Certain  it  is  that  Mr.  Burbank  has  produced 
mutants  without  number  in  the  course  of  his  ex- 
periments through  the  process  of  hybridization, 
— a  mutant  being  described  as  a  form  that  departs 
radically  from  the  type  of  its  seed  parent.  The 
particular  mutants  that  first  attracted  the  atten- 
tion of  Professor  De  Vries  bred  true  to  the  new 
type  from  seed,  thus  seeming  to  constitute  a  new 
race.  The  same  thing  is  true  of  many  of  the 
mutants  that  Mr.  Burbank  has  produced  by  hy- 
bridization. But  as  to  this  point,  there  is  oppor- 
tunity for  diversity  of  habit.  A  new  form  pro- 
duced by  hybridization  may  breed  true,  as  in  the 
case  of  Mr.  Burbank 's  Primus  berry,  but  it  is 
much  more  likely,  as  we  have  seen  illustrated,  to 
show  a  great  diversity  of  form  among  its  imme- 
diate progeny.  Some  of  these  forms  may  breed 
true,  while  others  will  fail  to  do  so. 

This  is  of  the  utmost  importance  to  the  plant 
developer,  particularly  in  the  case  of  annual 
plants  that  must  be  grown  from  seed.  In  the  case 
of  plants  that  can  be  reproduced  by  division  the 
matter  is  not  so  important,  as  any  new  variety 
developed  may  be  propagated  indefinitely  without 
use  of  the  seed.  Such  is  the  regular  method  of 
propagation,  as  we  have  seen,  in  the  case  of  the 

[152] 


MR.  BURBANK  INSPECTING  GARLIC  SEEDLINGS 

The    plants    are    specially    cross-bred    and    selected    specimens,    having    peculiar 
qualities  of  thrifty  growth,  as  well  as  exceptional  flavor. 


IN  THE  FLOWER  GARDEN 

orchard  fruits,  of  such  vegetables  as  the  potato, 
and  of  bulbous  plants  in  general. 

But  a  large  number  of  our  flowering  plants  are 
annuals  that  are  reproduced  solely  by  the  seed. 
With  these  it  is  obviously  a  matter  of  great  im- 
portance that  the  seedlings  should  reproduce  the 
qualities  of  the  parent,  otherwise  the  new  variety 
that  you  produce  would  have  no  permanency. 

It  is  precisely  here  that  the  patience  of  the 
plant  developer  is  most  often  put  to  a  test.  Very 
generally  the  new  variety  that  you  develop  by 
hybridization,  and  which  you  would  wish  to  per- 
petuate, does  not  breed  true  from  the  seed.  It 
becomes  necessary,  then,  in  order  that  your  new 
variety  shall  have  real  importance,  that  you 
should  practice  systematic  selective  line  breeding 
until  you  "fix"  the  desired  quality  or  qualities. 

To  this  end,  you  must  sow  the  seed  of  your  se- 
lected variety,  and  permit  all  the  seedlings  to  ma- 
ture. Among  the  hundreds  of  plants,  there  will 
probably  be  a  few  that  reproduce  the  attractive 
qualities  of  the  parent.  The  best  of  these  should 
be  carefully  inbred — self-fertilized — and  its  seed 
sown  next  season ;  and  a  similar  selection  followed 
up,  year  after  year,  if  need  be,  until  a  plant  is 
secured  all  the  seed  of  which  will  reproduce  the 
desired  quality. 

If  a  single  quality  is  in  question,  you  will  gen- 
erally be  able  to  "fix"  the  type  in  two  genera- 
tions. But  if  several  new  qualities  are  combined 
in  your  favored  variety,  it  may  be  necessary  to 
carry  out  the  selective  line  breeding  for  five  or 

[153] 


LUTHER  BURBANK 

six  generations.  Much  depends  on  whether  the 
qualities  under  observation  act  as  "  dominant "  or 
as  " recessive"  qualities  in  the  Mendelian  sense. 
The  exact  meaning  of  this  and  the  manner  of  test- 
ing have  already  been  explained,  and  will  be 
further  elaborated  in  another  connection. 

The  prime  essential,  however,  is  that  the  plants 
shall  be  rigidly  guarded  against  cross-fertiliza- 
tion. New  varieties  are  created  by  cross-polleniz- 
ing ;  they  are  fixed  by  self-pollenizing.  In  a  care- 
fully conducted  experiment,  it  will  be  well  to  cover 
the  plant  with  a  net,  to  keep  the  bees  from  inter- 
fering, meantime  hand-pollenizing  each  blossom 
with  pollen  from  other  flowers  of  the  same  plant. 

METHODS   OF   POLLENIZING 

In  order  to  carry  out  this  all-important  business 
of  pollenizing  (cross-breeding  in  some  cases,  in- 
breeding in  others),  it  will  obviously  be  necessary 
to  study  the  anatomical  structure  of  different 
flowers.  The  principle  is  always  the  same — pollen 
from  one  flower  is  to  be  carried  to  the  pistil  of 
another.  But  some  flowers  have  the  stamens  ar- 
ranged in  a  peculiar  way,  and  the  casual  inspector 
may  not  at  first  glance  recognize  them. 

Plants  of  the  iris  tribe,  for  example,  have  a 
peculiar  mechanism  whereby  the  pollen  is  de- 
posited on  the  back  of  a  bee,  and  then  is  scraped 
off  by  the  pistil  of  the  next  flower  that  the  bee 
visits.  The  amateur  botanist  might  not  at  first 
glance  recognize  the  pistil,  and  hence  might  be 

[154] 


IN  THE  FLOWER  GARDEN 

puzzled  as  to  the  way  in  which  pollenation  is  to 
be  effected. 

Again,  the  milkweed  has  its  pollen  in  sacks  ar- 
ranged like  saddle-bags,  designed  to  entangle  the 
legs  of  the  bee,  and  the  amateur  might  not  recog- 
nize them  as  bearers  of  pollen. 

A  little  study  of  the  mechanism  of  the  different 
flowers  with  the  aid  of  a  magnify  ing-glass  will 
solve  all  of  these  difficulties. 

Meantime  the  insight  that  will  thus  be  gained 
into  the  curious  modifications  of  structure 
through  which  nature  guards  against  the  self- 
fertilization  of  the  flower  will  prove  a  source  of 
perennial  interest.  Theoretical  botany  and  prac- 
tical plant  development  go  hand  in  hand,  and  the 
flower  garden  is  the  ideal  place  to  make  initial 
studies  of  one  and  practical  tests  of  the  other. 


[155] 


CHAPTER  VIII 
THEORY  AND  PRACTICE 

I  HAVE  all  along  attempted  to  make  it  clear 
that  the  fundamental  principles  of  plant 
breeding  are  simple,  and  that  the  amateur 
may  begin  experiments  and  even  carry  them  to 
interesting  conclusions  with  comparative  ease.  It 
is  desirable  now  to  supplement  what  has  previ- 
ously been  said  by  calling  attention  to  some  of  the 
complications  that  are  sure  to  arise  as  the  work 
of  plant  breeding  progresses ;  and  in  so  doing,  of 
course,  to  point  out  clearly  how  these  complica- 
tions may  be  met. 

Let  us  first  recall  what  has  been  outlined  in  the 
previous  articles  as  to  Mendelian  heredity.  We 
saw  that  when  the  flower  of  a  tall  pea  vine  is 
fertilized  with  pollen  from  the  flower  of  a  short 
pea  vine  the  progeny  will  all  be  tall;  but  that  in 
the  second  generation  one  vine  in  four  will  be 
short,  like  one  of  the  grandparents.  Thus  in  the 
vine  of  the  first  filial  generation  the  hereditary 
factors  for  tallness  may  be  said  to  be  "  dominant, " 
since  they  make  themselves  manifest,  and  the 
factors  for  shortness  may  be  said  to  be  "re- 
cessive," since  they  are  submerged  and  for  the 
time  being  inoperative.  But  these  recessive  fac- 
tors come  to  the  surface,  as  it  were,  in  one  in 

[156] 


THEORY  AND  PRACTICE 

four,  on  the  average,  of  the  progeny  of  the  next 
generation.  And  it  is  observed  that  the  short  vine 
in  which  the  recessive  factor  thus  again  makes 
itself  manifest  will  breed  true  to  shortness,  the 
factors  for  tallness  apparently  being  altogether 
eliminated  from  its  germ-plasm. 

Meantime,  as  just  noted,  for  every  short  vine  of 
this  second  filial  generation  there  are  three  tall 
ones;  and  further  breeding  tests  will  show  that, 
while  these  three  vines  look  just  alike,  there  are 
fundamental  differences  in  their  germ-plasm ;  for 
one  of  them  will  breed  true  to  tallness  (being  a 
pure  dominant,  as  the  saying  is),  while  the  other 
two  are  " mixed  dominants"  and  will  have 
progeny  of  which,  in  each  group  of  four,  one  will 
be  short  (pure  recessive),  one  tall  (pure  dom- 
inant), and  two  also  tall  but  of  mixed  germ-plasm 
like  their  parents. 

The  essential  point  is  simply  that  any  char- 
acter that  acts  as  recessive  in  the  Mendelian  sense 
will  be  seemingly  eliminated  in  the  first-genera- 
tion cross  that  brings  it  in  combination  with  the 
opposite  character;  but  that  the  recessive  char- 
acter will  reappear  in  the  next  generation,  and 
will  then  breed  true.  So  when  you  find  that  you 
are  dealing  with  a  recessive  quality,  you  may  fix 
it  in  the  third  generation  without  difficulty.  But 
the  dominant  quality,  on  the  other  hand,  although 
it  makes  itself  manifest  in  all  the  first-generation 
progeny,  and  in  three  out  of  four  of  the  second- 
generation  progeny,  has  to  meet  the  masked 
rivalry  of  recessive  factors  in  two  out  of  three 

[157] 


LUTHER  BURBANK 

of  its  second-generation  members,  so  that  these 
cannot  breed  true. 

When  you  wish  to  fix  a  dominant  quality,  there- 
fore, you  must  save  the  seed  of  each  individual 
and  plant  it  in  separate  plots.  Only  in  this  way 
can  you  determine  which  individual  is  a  pure 
dominant,  and  hence  will  breed  true.  If  you  mix 
the  seeds  of  your  dominants,  you  may  go  on  for 
generations,  groping  blindly  in  the  effort  to  fix 
a  new  race,  without  success. 

It  is  highly  important  to  get  these  relations  of 
dominant  and  recessive  factors  in  Mendelian 
heredity  clearly  in  mind.  Indeed,  the  principle 
that  mutually  exclusive  pairs  of  qualities  are  inde- 
pendently segregated  and  redistributed  in  the  sec- 
ond generation  of  a  hybrid  progeny  doubtless  ex- 
ceeds in  importance  all  other  aspects  of  the 
problem  of  plant  development.  It  was  through 
independent  discovery  of  this  law  of  heredity  that 
Mr.  Burbank  was  enabled  to  make  the  major  part 
of  his  conquests  in  the  domain  of  practical  plant 
breeding. 

DEALING   WITH   COMPLEX  FACTOBS 

If  you  have  grasped  the  essential  principles  of 
this  Mendelian  inheritance,  your  effort  to  com- 
bine the  qualities  of  two  different  varieties  of 
species  of  plant  will  represent  a  comparatively 
simple  experiment  so  long  as  you  have  only  one 
or  two  characters  in  mind.  Suppose,  by  way  of 
illustration,  that  you  have  in  your  garden  a  gladi- 

[158] 


THEORY  AND  PRACTICE 

olus  with  robust  stalk  that  bears  small  flowers, 
and  another  variety  with  small  stalk  that  bears 
large  flowers.  By  crossing  the  two,  and  then  in- 
breeding the  cross-bred  progeny,  you  may  expect 
that  in  the  second  generation  you  will  secure  some 
plants  that  will  bear  large  flowers  on  robust  stalks, 
combining  the  good  traits  of  the  grandparents. 

But,  as  your  experiments  are  extended,  you  will 
presently  be  confronted  with  instances  in  which 
the  case  is  not  so  simple.  You  will  be  concerned 
not  merely  with  the  size  of  stalk  and  size  of  flower 
of  your  gladiolus,  but  with  questions  of  color,  of 
abundant  bearing,  and  of  keeping  qualities  as  well. 
And  you  should  know  that  with  the  inclusion  of 
each  new  character  the  application  of  the  Men- 
delian  formula  becomes  increasingly  complicated. 
The  fundamental  principle,  as  just  outlined,  is  not 
altered,  to  be  sure.  Each  pair  of  qualities  (tall 
stalk  versus  short  stalk,  large  flower  versus  small 
flower,  red  flower  versus  white  flower,  etc.)  will 
be  carried  forward  quite  independently  of  all  the 
other  characters,  and  recessive  traits  will  tend  to 
reappear  in  one  individual  in  four  of  the  second- 
generation  progeny.  But,  according  to  the  simple 
law  of  chances,  it  comes  about  that  where  two 
pairs  of  Mendelian  factors  are  in  question  the 
recessive  factors,  although  appearing  in  one  in- 
dividual in  four  of  the  progeny,  will  be  combined 
in  the  same  individual  in  only  one  case  in  sixteen. 

And  when  three  pairs  of  hereditary  factors  are 
in  question — for  example,  tall  or  short  vines,  pink 
or  white  flowers,  and  yellow  or  green  pods,  in 

[159] 


LUTHER  BURBANK 

the  case  of  Mendel's  peas — the  chance  that  the 
three  successive  qualities  will  be  combined  in  the 
same  individual  of  the  second-generation  progeny 
is  only  one  in  sixty-four.  When  four  qualities 
are  under  consideration,  the  chance  that  they  will 
be  combined  in  any  particular  way  is  but  one  in 
two  hundred  and  fifty-six.  And  with  the  inclusion 
of  still  other  qualities,  the  geometrical  ratio  pro- 
gresses in  such  startling  fashion  as  to  give  us  as- 
surance that  if  we  are  attempting  to  combine  ten 
different  qualities  in  any  given  combination,  the 
chance  of  doing  so  is  about  one  in  a  million. 

Your  first  thought  will  be,  perhaps,  that  you 
are  not  likely  to  consider  more  than  two  or  three 
qualities  as  desirable  in  the  case  of  any  given 
plant.  But  a  moment's  reflection  will  show  that 
here  you  are  in  error.  Let  us,  for  example,  con- 
sider the  perfected  varieties  of  gladioli  that 
have  been  developed  in  Mr.  Burbank's  experiment 
gardens.  We  shall  find  that  there  is  scarcely  a 
quality  of  bulb  or  stalk  or  flower  that  has  not  been 
modified  in  one  direction  or  another. 

The  bulb  has  been  made  to  produce  bulblets 
rapidly;  they  have  been  rendered  hardy;  and  in 
particular  they  have  been  made  relatively  immune 
to  disease.  The  stalks  have  been  caused  to  grow 
to  gigantic  size,  to  stand  firmly  erect,  and  to  bear 
flowers  not  merely  on  one  side,  as  they  were  for- 
merly wont  to  do,  but  in  spirals  that  show  the 
flowers  in  a  solid  cluster,  the  blossoms  facing  in 
all  directions.  The  flowers  themselves  have  been 
very  markedly  increased  in  size,  and  given  bril- 

[160] 


. 


THEORY  AND  PRACTICE 

liancy  of  coloration  and  remarkable  keeping  quali- 
ties. Some  of  them  have  been  made  to  bear 
double  rows  of  petals. 

Here,  then,  it  appears  that  not  fewer  than  ten 
separate  and  distinct  qualities  of  the  gladiolus 
plant  have  been  under  consideration  in  the  course 
of  Mr.  Burbank 's  experiments.  It  is  obvious  that 
the  plant  breeder  could  not  be  satisfied  unless  the 
good  qualities  were  all  combined  in  the  same  in- 
dividual plant.  It  would  not  at  all  suffice  that  one 
plant  should  have  a  hardy  bulb  while  bearing 
poor  flowers;  or  that  another  plant  should  have 
a  splendid  array  of  flowers  on  a  frail  stalk;  or, 
again,  that  flowers  of  great  beauty  should  have 
poor  keeping  quality.  All  the  good  qualities  must 
be  combined  in  the  same  individual. 

Suppose  that  Mr.  Burbank  started  with  one 
gladiolus  plant  having  a  splendid  stalk,  another 
having  an  immune  bulb,  a  third  with  flowers  of 
large  size,  a  fourth  with  flowers  of  good  keeping 
quality,  etc.  He  could  combine  the  plants  two 
and  two  by  cross-pollenizing ;  and,  by  recombining 
again  and  again,  in  the  fourth  generation  he  would 
have  blended  the  strains  of  all  the  ten  original 
parents.  But,  as  we  have  seen,  the  chance  that 
any  individual  seedling  of  the  next  generation 
would  combine  the  desirable  traits  of  the  ten  orig- 
inal parent  forms  in  just  the  right  proportion 
is  only  one  in  a  million. 

That  is  why  Mr.  Burbank  raises  his  seedlings 
in  such  immense  profusion. 

When  the  gladiolus  experiments  were  under 
[161] 


LUTHER  BURBANK 

way,  for  example,  you  might  see  in  his  greenhouse 
box  after  box,  each  showing  tens  of  thousands  of 
gladiolus  seedlings.  Day  after  day  the  scrutiny 
of  these  multitudes  of  little  plants  is  continued, 
the  obvious  weaklings  being  weeded  out,  until  a 
fraction  of  the  original  number  remained  to  be 
transplanted  to  the  fields,  and  permitted  to  de- 
velop and  reveal  their  possibilities.  But  even 
after  all  the  obvious  undesirables  were  eliminated, 
there  would  still  remain  hundreds  of  thousands 
of  plants  to  be  set  out  in  long  rows  in  the  experi- 
ment garden  at  Sebastopol,  each  given  equal  op- 
portunity with  all  the  others.  And,  as  we  have 
seen,  the  ultimate  result  of  the  experiment  would 
be  the  selection  by  Mr.  Burbank  at  flowering  time 
of  perhaps  a  dozen  or  a  score  among  all  the  hun- 
dreds of  thousands  as  representing  the  closest 
approximation  to  the  ideal  type  at  which  he  aimed. 
Or  perhaps  a  single  plant  would  be  found  among 
the  myriads  that  combined  in  fair  measure  all  the 
good  qualities  that  were  sought.  The  experiment 
would  then  be  completed  by  "line  breeding "  from 
this  individual,  saving  all  its  seeds,  and  selecting 
among  its  progeny  (which  are  sure  to  show  a  con- 
siderable range  of  variation)  those  that  are  best, 
until  a  race  has  been  developed  in  which  the  de- 
sired qualities  are  accentuated  to  the  maximum. 

STUDIES  IN   COLOB  VAEIATION 

Probably  you  could  not  do  better  in  beginning 
your  experiments  with  the  ornamental  plants  of 

[162] 


THEORY  AND  PRACTICE 

the  dooryard  than  to  work  with  reference  to  the 
modification  of  the  color  of  the  flowers. 

There  are  numerous  familiar  plants  with  any 
one  of  which  you  might  work  to  advantage, — f or 
example,  the  gladiolus,  the  dahlia,  the  verbena,  or 
the  nasturtium.  All  of  these  plants  show  great 
color  variation.  In  cross-breeding  and  selecting 
to  secure  new  combinations  of  color,  you  are  deal- 
ing with  a  restricted  group  of  hereditary  factors, 
and  hence  it  will  not  be  necessary  to  have  large 
numbers  of  individual  plants.  Moreover,  color  in 
flowers  is  a  new  or  recent  development  in  the  evo- 
lutionary sense,  and  hence  modifications  of  color 
are  more  readily  brought  about  than  changes  of 
root  or  stem  or  leaf. 

It  is  probable  that  all  flowers  were  originally 
green,  and  that  in  the  course  of  evolutionary  de- 
velopment some  flowers  changed  from  green  to 
blue  and  then  to  indigo  and  violet,  while  others 
ran  the  chromatic  scale  in  the  other  direction, 
varying  from  green  through  yellow  and  orange 
to  red.  Eed  and  violet  flowers  are  therefore  prob- 
ably new  in  the  evolutionary  sense,  blue  and  yellow 
flowers  being  old.  White  flowers  may  be  due  to 
having  air  in  their  cells,  or  to  the  blending  of  other 
colors — say  yellow  and  blue.  Yellow  flowers  may 
be  due  to  the  blending  of  red  and  green.  In 
general,  the  mixture  of  factors  for  color  in  the 
heredity  of  a  flower  may  rival  in  complexity  the 
mixture  of  pigments  on  the  canvas  of  an  artist. 

The  greatest  interest  of  all,  perhaps,  for  the 
amateur  plant  developer,  attaches  to  the  bringing 

[163] 


LUTHER  BUKBANK 

out  of  unexpected  colors  that  are  submerged  and 
hidden  by  more  recently  developed  colors.  As 
previously  suggested,  it  is  like  the  work  of  restor- 
ing an  old  masterpiece  by  removing  the  pigment 
of  a  modern  painting  overlying  it. 

It  is  at  least  a  plausible  theory  that  new  quali- 
ties tend  to  be  dominant  and  old  qualities  re- 
cessive in  the  Mendelian  sense,  when  brought 
in  opposition  through  cross-breeding.  Generally 
speaking,  then,  it  may  be  expected  that  in  cross- 
ing a  red  flower  with  a  white  one  of  the  same 
species  the  progeny  will  be  red.  Violet  crossed 
with  white  usually  gives  violet.  Between  yellow 
and  blue  there  may  not  be  much  to  choose  in  point 
of  date  of  origin,  and  the  result  of  a  crossing  may 
be  doubtful. 

Any  of  the  flowers  mentioned  may  be  worked 
with  to  advantage  along  these  lines.  An-  interest- 
ing wild  flower  showing  similar  possibilities  is 
the  Indian  paint  brush  or  painted  cup  (Castilleia). 
Specimens  of  this  growing  in  the  same  neighbor- 
hood may  vary  from  scarlet,  crimson,  orange, 
yellow,  and  purple  to  pure  white.  Even  the  same 
individual  may  show  flowers  having  most  of  these 
colors.  Mr.  Burbank  suggests  that  the  amateur 
might  advantageously  work  with  the  painted  cup 
in  an  effort  to  remove  the  overlying  colors  and 
reveal  the  pure  blue;  also  to  fix  the  different 
colors  in  different  races. 

An  interesting  illustration  of  curious  and  unex- 
pected results  that  may  be  attained  is  furnished 
by  one  of  Mr.  Burbank 's  hybrid  pinks,  in  which 

[164] 


THEORY  AND  PRACTICE 

the  individual  flower  varies  in  color,  changing 
from  one  shade  to  another  in  the  course  of  twenty- 
four  hours. 

In  the  morning  on  first  opening  the  flowers  are 
pure  white,  by  noon  they  are  a  bright  pink,  and 
toward  evening  they  have  changed  to  a  deep  crim- 
son. All  the  flowers  at  present  under  considera- 
tion furnish  illustrations  of  dominance  of  one 
color  factor  over  another,  and  on  occasion  of  the 
blending  of  factors  to  produce  new  colors;  but 
this  case  in  which  first  one  color  and  then  another 
is  dominant  in  the  same  flower  is  altogether  out 
of  the  ordinary. 

ACCENTUATING  DESIRED   CHARACTERS 

It  remains  to  be  said  that  the  distribution  of 
the  various  qualities  of  the  plant  into  opposing 
couples  showing  dominance  and  recessiveness  is 
by  no  means  so  clean-cut  and  explicit  in  every 
case  as  the  instances  just  cited  might  lead  one  to 
expect.  In  point  of  fact,  it  appears  to  be  true  that 
it  is  only  the  qualities  that  are  of  comparatively 
recent  origin  in  the  evolutionary  sense  that  clearly 
Mendelize.  Such  qualities,  for  example,  as  the 
precise  length  of  stem,  color  of  flower,  and  color  of 
seed  pod  are  far  less  fundamental  than  the  es- 
sential qualities  of  form  and  anatomical  structure 
of  stem  and  leaf,  and  the  shape  and  arrangement 
of  the  petals  and  the  essential  organs  of  the 
flower.  When  these  fundamentals  are  in  ques- 
tion, the  hybrid  progeny  usually  show  a  blending 

[165] 


LUTHER  BURBANK 

of  the  traits  of  the  parents  without  clear  dom- 
inance of  one  quality  over  another. 

But  even  where  these  qualities  are  blended  in 
the  first  generation,  there  is  likely  to  be  a  segre- 
gation and  redistribution  along  Mendelian  lines 
in  the  second  generation, — giving  rise  to  the  phe- 
nomenon which  breeders  have  been  accustomed 
to  speak  of  as  reversion  in  one  direction  or  the 
other  toward  the  parental  types.  So  you  will  do 
well  to  be  on  the  lookout  for  the  phenomena  of 
Mendelian  heredity  in  the  second  generation,  even 
where  you  fail  to  find  clear  evidence  of  the  dom- 
inance of  a  character  in  the  first  hybrid  genera- 
tion. 

If,  for  example,  you  were  to  cross  an  orange 
poppy  and  a  white  one,  as  Mr.  Burbank  once  did, 
securing  only  crimson-flowered  progeny,  you  could 
carry  the  experiment  forward  another  generation 
with  full  confidence  that  there  would  be  interesting 
color  revelations,  enabling  you  perhaps  to  ana- 
lyze the  component  colors  of  the  original  parents 
in  the  second  generation.  In  this  particular  case 
it  is  not  unlikely  that  the  original  orange  and 
white  flowers  contained  blended  pigments — per- 
haps red  and  yellow  in  one  case,  and  yellow  and 
blue  in  the  other — and  the  breaking  up  and  re- 
distribution of  these  hereditary  factors  through 
cross-breeding  might  prepare  the  way  for  the 
bringing  out  of  hidden  colors,  leading  ultimately, 
perhaps,  to  the  production  of  a  blue  poppy. 

This  illustration  gives  us  a  clew  to  yet  another 
important  aspect  of  our  problem  of  plant  breed- 

[166] 


THEORY  AND  PRACTICE 

ing.  In  the  main  discussion  of  Mendelian  heredity 
above,  we  have  spoken  as  if  the  thing  contem- 
plated were  the  recombination  of  qualities  that 
are  already  patent  in  one  parent  or  the  other  of 
the  original  cross.  But,  in  point  of  fact,  the  ob- 
ject sought  by  the  plant  breeder  often  goes  far 
beyond  the  mere  combination  of  existing  quali- 
ties, as  the  case  of  the  blue  poppy  at  once  sug- 
gests. 

The  same  thing  is  illustrated  by  a  beautiful  blue 
gladiolus  which  Mr.  Burbank  developed  by  cross- 
ing an  imported  gladiolus  having  a  small  purplish 
flower  with  a  large  white  one  of  his  own  develop- 
ment. The  mingling  of  hereditary  factors  here 
gave  new  combinations,  and  ultimately  produced 
a  large  flower  from  which  the  obscuring  pigments 
had  been  removed,  so  that  an  underlying  blue, 
recessive  to  most  other  pigments,  was  revealed. 

It  may  be  said  that  Mr.  Burbank 's  plant  devel- 
opments have,  as  a  rule,  been  similarly  carried 
forward  until  qualities  are  so  accentuated  or  modi- 
fied as  to  seem  of  a  quite  different  order  from  the 
qualities  of  the  parent  forms.  Here,  for  example, 
is  a  giant  amaryllis  with  a  flower  almost  a  foot 
in  diameter,  the  product  of  experiments  in  hy- 
bridizing and  selection  that  involved  no  parent 
plant  having  a  flower  more  than  five  or  six  inches 
in  diameter.  Here  is  another  hybrid  amaryllis 
bulb  which  puts  forth  a  new  bulblet  every  week, — 
fifty  of  them  in  a  year, — although  the  parent 
forms  from  which  this  variety  was  developed  were 
accustomed  to  produce  only  half  a  dozen  new  bulb- 

[167] 


LUTHER  BURBANK 

lets  in  a  season.  Here  is  a  hybrid  between  a 
crinum  and  an  amaryllis,  the  bulb  of  which  is  far 
larger  than  a  man's  head,  although  neither  parent 
had  a  bulb  of  unusual  dimensions.  And  yonder 
is  a  hybrid  gladiolus  with  a  double  row  of  petals, 
sprung  from  parents  that  bore  flowers  with  no 
suggestion  of  doubleness. 

UNEARTHING  EEMOTE   HEREDITIES 

In  attempting  to  explain  these  anomalies,  we 
are  led  to  conclude  that  every  individual  plant 
carries  in  its  germ-plasm  a  multitude  of  heredi- 
tary factors  that  are,  as  it  were,  submerged  be- 
neath other  factors  and  prevented  from  making 
their  presence  tangibly  manifest.  There  is  appar- 
ently no  limit  to  the  number  of  generations 
through  which  a  hereditary  factor  may  be  carried 
latent  and  seemingly  impotent,  yet  always  ready 
to  manifest  itself  when  the  opportunity  arises. 
And  the  opportunity  may  come  through  a  hybrid- 
ization that  brings  new  coteries  of  hereditary  fac- 
tors into  the  combination,  with  resultant  redis- 
tributions that  no  one  could  predict,  but  which 
may  be  very  striking  and  highly  suggestive  and 
interesting  in  their  manifestations. 

The  gigantic  trumpet  of  the  hybrid  amaryllis 
and  the  enormous  bulb  of  the  hybrid  crinum  are 
reminiscent  of  past  ages  when  remote  ancestors 
of  these  plants  grew  under  favoring  tropical  con- 
ditions of  an  earlier  geographical  era,  and  put 
forth  flowers  and  bulbs  of  which  the  best  present- 

[168] 


BURBANK  ONIONS  GROWN  FOR  SEED. 
Mr.  Burbank  has  worked  extensively  with  the  onion,  as  with 
numerous  other  members  of  the  tribe  of  alliums.  Here  we  see  a 
field  of  perfected  Burbank  onions  that  have  distinctly  ornamental 
flowers.  The  excellent  character  of  the  bulbs  may  be  inferred  from 
the  size  and  vigorous  development  of  the  tops. 


THEORY  AND  PRACTICE 

day  specimens  are  but  dwarfed  and  insignificant 
replicas. 

Similarly  the  double  flowers  that  form  so  at- 
tractive a  feature  in  our  gardens — roses,  dahlias, 
marigolds,  and  the  rest — are  probably  reminis- 
cent of  clustered  flowers  of  the  antique  world. 
What  is  now  the  composite  head  of  a  single  dahlia 
or  marigold  or  daisy  was  probably,  in  its  pri- 
mordial state,  a  cluster  of  flowers.  Through  nat- 
ural selection  such  a  cluster  made  an  experiment 
in  communism,  in  which  finally  hundreds  of  flow- 
ers were  grouped,  with  a  single  circle  of  florets 
to  advertise  their  location  to  the  insects.  This 
represented  great  economy,  and  the  plan  became 
enormously  popular,  so  that  the  composites  are 
among  the  most  abundant  of  flowers.  But  each 
individual  blossom  in  a  composite  flower  head  car- 
ries in  its  germ-plasm  the  factors  for  the  develop- 
ment of  an  independent  corolla,  and  under  favor- 
ing conditions — through  hybridization  or  through 
changed  environment — this  potentiality  is  realized 
in  the  production  of  what  we  term  a  double  flower. 

In  this  way  only  can  we  explain  such  a  phe- 
nomenon as  the  rapid  production  of  races  of 
double  dahlias  in  the  relatively  short  period  since 
the  single  dahlia  was  brought  from  Mexico  and 
given  a  place  in  the  cultivated  flower  garden. 


[169] 


CHAPTER  IX 

BURBANK'S  METHOD  OF  BEAUTIFYING 
LAWN  AND  DOORYARD 

THIS  chapter  tells  how  to  apply  Mr.  Bur- 
bank's  method  to  the  care  and  beautifica- 
tion  of  the  lawn  and  dooryard  in  their  en- 
tirety. It  deals  not  alone  with  the  lawn  itself, 
but  with  the  bed  flowers  and  ornamental  vines  that 
beautify  the  dooryard.  Mr.  Burbank  has  pro- 
duced wonderful  new  flowering  vines  and  numer- 
ous ornamental  shrubs  of  great  beauty.  His  work 
with  the  canna,  gladiolus,  watsonia,  amaryllis, 
and  rose  has  been  as  remarkable  as  almost  any 
other  work  that  he  has  done. 

Many  visitors  to  Mr.  Burbank 's  home  in  Santa 
Rosa  in  recent  years  have  been  much  interested 
in  the  lawn  about  his  dwelling. 

At  a  little  distance  this  looked  much  like  any 
other  lawn  that  is  well  covered  with  grass.  But 
closer  inspection  showed  that  the  velvety  cover- 
ing was  not  made  by  grass,  but  by  a  trailing  vine. 
It  was  in  reality  a  species  of  verbena  of  a  peculiar 
type.  It  is  known  to  the  botanist  as  Lippia,  and 
this  word  serves  as  well  as  any  other  for  a  popular 
name. 

Lippias  of  several  species  were  sent  to  Mr.  Bur- 
bank  from  Chile,  and  he  has  cultivated  and  devel- 

[170] 


LAWN  AND  DOCKYARD 

oped  two  or  three  varieties  with  especial  refer- 
ence to  their  utility  as  substitutes  for  lawn  grass. 
When  Mr.  Burbank  first  procured  the  seed  of  the 
wild  species  he  observed  a  good  deal  of  variation 
among  the  seedlings,  and  in  the  second  season 
he  raised  about  ten  thousand  plants,  each  one  of 
which  was  given  a  little  space  in  order  that  its 
individual  peculiarities  as  to  rapidity  of  growth, 
tendency  to  spread,  and  color  of  foliage  might  be 
tested. 

From  among  these  ten  thousand  plants  about 
half  a  dozen  were  saved,  and  the  descendants  of 
these  constitute  several  varieties  of  lippias  that 
have  striking  peculiarities.  One  of  these  will 
spread  on  an  ordinary  soil  over  a  circle  about 
ten  feet  in  diameter.  This  form,  Mr.  Burbank 
points  out,  would  be  very  valuable  for  growing 
in  sunny  places,  and  in  particular  along  irrigat- 
ing ditches  or  river  banks  where  the  soil  is  sub- 
ject to  wash.  Other  varieties  grow  less  rapidly, 
but  have  small  leaves  that  lie  very  close  to  the 
ground,  making  a  most  beautiful  and  satisfactory 
velvety  lawn. 

There  is  a  marked  difference  in  color  in  the 
different  varieties,  so  that  charming  contrasts  may 
be  produced  by  planting  different  portions  of  the 
lawn  with  different  varieties. 

In  addition  to  their  rapid  and  compact  growth, 
Mr.  Burbank 's  perfected  lippias  are  adapted  to 
dry  soil,  requiring  not  one-tenth  the  water  that 
blue-grass  or  other  ordinary  lawn  grass  requires, 
and  keeping  in  good  condition  with  a  fraction  of 

[171] 


LUTHER  BURBANK 

the  care  that  must  be  bestowed  on  lawns  of  blue- 
grass  or  clover. 

Curiously  enough  the  lippia  lawn  makes  the 
best  appearance  where  it  is  frequently  trod  upon 
and  subjected  to  rough  treatment. 

All  in  all,  then,  the  developed  lippia  constitutes 
a  remarkable  lawn  cover,  and  one  that  must  in- 
crease in  popularity  in  all  climates  to  which  it 
is  adapted.  Unfortunately  the  plant  is  rather 
tender,  and  is  likely  to  winter-kill  in  the  northern 
parts  of  the  United  States.  But  it  is  expected 
that  hardy  varieties  will  be  developed  by  further 
experiments  in  selective  breeding,  and  the  lippia 
will  then  become  a  formidable  rival  of  the  blue- 
grass  for  lawns  everywhere,  and  in  particular  in 
regions  where  there  are  long  periods  of  summer 
drought. 

OTHER   SUBSTITUTES  FOE   GEASS 

Very  recently  Mr.  Burbank  has  experimented 
successfully  with  several  other  substitutes  for 
grass. 

He  has  found  two  plants  that  are  superior  to 
the  lippias  for  growth  in  soil  subject  to  washing ; 
for  example,  along  creeks,  or  irrigating  ditches, 
or  on  hillsides.  One  of  these  plants  is  a  species 
of  Mesembryanthemum,  which  grows  along  most 
seacoasts.  This  produces  an  enormous  amount  of 
dense  foliage,  which  is  not  moved  even  by  a  very 
heavy  stream  of  water. 

The  other  plant  is  a  selected  variety  of  the 
[172] 


LAWN  AND  DOCKYARD 

trailing  myrtle  (Vinca  minor).  This  forms  a 
great  mass  of  long  white  roots,  and  long  vines 
with  abundant  evergreen  foliage,  which  resist 
stream  wash  by  shingling  the  whole  surface  so 
that  the  water  can  scarcely  reach  the  soil.  Sev- 
eral other  plants  are  under  observation  with  refer- 
ence to  their  possible  utility  as  substitutes  for 
blue-grass  on  ordinary  lawns;  in  particular  the 
attempt  being  made  to  develop  varieties  that  are 
hardier  than  the  lippias. 

Among  the  most  interesting  of  experiments 
thus  far  conducted  are  those  having  to  do  with 
the  trailing  species  of  hypericum  from  the  moun- 
tains of  eastern  Chile.  On  the  lawn  in  front  of 
Mr.  Burbank's  dwelling  at  the  present  moment 
this  plant  has  taken  the  place  of  the  lippias.  It 
makes  a  close  mat  of  green,  and  it  does  not  turn 
brown  in  winter.  It  grows  somewhat  less  rapidly 
than  the  lippia,  but  there  is  good  promise  that 
selected  varieties  will  make  an  excellent  lawn 
cover. 

Somewhat  similar  species  of  hypericum  have 
recently  been  introduced  by  Mr.  Burbank  from 
Russia  and  from  other  parts  of  central  and 
northern  Europe.  These  show  the  same  creeping 
habit,  and  no  doubt  will  be  hardy  everywhere. 
Even  the  first  generation  from  the  wild  native 
plants,  these  hypericums  show  a  wonderful  varia- 
tion as  to  rapidity  and  compactness  of  growth. 
There  is  every  reason  to  expect,  then,  that  a  few 
years  of  selective  breeding,  under  Mr.  Burbank's 
skillful  supervision,  will  supply  a  lawn  plant  for 

[173] 


LUTHER  BURBANK 

all  climates  in  many  ways  superior  to  anything 
hitherto  known.  Mr.  Burbank  makes  this  predic- 
tion with  some  confidence ;  adding,  however,  that 
the  new  plant  may  be  a  little  more  difficult  to 
establish  than  ordinary  lawn  grass. 

All  the  hypericums  will  stand  a  great  amount 
of  drought  and  ill  treatment.  Tramping  does  not 
injure  them,  and  they  may  be  moved  like  ordinary 
lawn  grass.  Observation  of  the  varieties  already 
under  cultivation  at  Santa  Rosa  gives  assurance 
that  here  is  material  from  which  a  valuable  new 
type  of  lawn  cover  will  be  developed.  There  is 
no  reason  why  the  amateur  should  not  make 
experiments  in  selective  breeding  with  the  hy- 
pericums, even  in  localities  where  the  more  tender 
lippia  cannot  be  grown. 

OKDINAKY   LAWNS  AND   THEIR   CAEE 

Until  the  lippias  have  been  rendered  hardy, 
however,  or  the  hypericum  or  the  other  plants 
more  fully  developed,  most  residents  of  the  north- 
ern climates  must  be  content  with  the  lawn  grasses 
of  the  old  familiar  type,  with  the  blue-grass  at 
the  head  of  the  list. 

Seeds  for  these  grasses  vary  a  good  deal  in 
quality,  and  Mr.  Burbank  urges  that  they  shall  be 
secured  only  of  a  reputable  dealer.  Pure  blue- 
grass  he  thinks  better  for  the  ordinary  lawn  than 
any  mixture. 

The  grasses  themselves  offer  opportunity  for 
great  improvement  through  hybridizing  and  se- 

[174] 


LAWN  AND  DOORYARD 

lective  breeding,  but  the  hybridizing  of  plants 
that  have  such  small  and  inconspicuous  flowers 
requires  a  good  deal  of  skill.  To  such  as  wish  to 
undertake  it,  however,  it  may  be  said  that  the 
process  of  cross-fertilization  is  in  no  wise  differ- 
ent in  principle  from  that  employed  in  the  case 
of  other  flowers.  It  will  be  necessary  in  many 
cases  to  work  with  a  magnifying-glass,  and  deli- 
cacy of  manipulation  is  essential.  But  if  you  have 
acquired  skill  through  practice  on  the  larger 
flowers  of  orchard  and  garden,  the  fertilizing  of 
the  grasses  will  offer  no  insuperable  difficulties. 

In  particular,  you  may  find  interest  in  experi- 
menting with  some  of  the  large  ornamental 
grasses,  such  as  pampas  grass,  which  may  readily 
be  hybridized,  and  greatly  developed  as  to  size 
and  artistic  quality  of  the  plume-like  flower  heads. 
Some  of  the  pampas  grasses  bear  the  staminate 
and  pistillate  flowers  in  separate  panicles,  and 
hence  may  be  cross-fertilized  by  merely  dusting 
one  flower  cluster  against  another.  At  the  time 
when  the  pampas  grasses  were  more  in  vogue  than 
they  now  are,  Mr.  Burbank  developed  many  inter- 
esting varieties,  using  precisely  the  same  methods 
of  hybridization  and  selection  that  have  been  de- 
tailed in  connection  with  the  development  of  other 
plants. 

Other  grasses  with  which  anyone  may  work, 
and  which  give  promise  of  results  of  vast  economic 
importance,  are  the  familiar  cereals,  wheat,  oats, 
and  rye.  Here  fertilization  is  difficult,  as  the 
flowers  are  borne  in  closed  receptacles;  but,  on 

[175] 


LUTHER  BURBANK 

the  other  hand,  there  is  little  danger  of  vitia- 
tion of  the  experiments  through  accidental  cross- 
ing. 

As  an  instance  of  what  may  be  done,  it  may  be 
noted  that  Professor  Biffin,  at  Cambridge  Uni- 
versity, England,  recently  succeeded  in  develop- 
ing a  variety  of  wheat  that  promises  to  revolu- 
tionize the  wheat-growing  industry  in  England, 
by  combining  the  strains  of  a  hardy  wheat  of 
poor  quality  with  a  weak-stalked  wheat  having 
a  good  head.  The  experiment  was  carried  out 
along  Mendelian  lines,  and  perfected  in  three  gen- 
erations, giving  the  farmers  of  England  a  wheat 
of  good  quality,  immune  to  the  rust  that  had 
devastated  their  fields. 

Mr.  Burbank  has  under  way  a  series  of  experi- 
ments in  which  he  has  crossed  all  available  va- 
rieties of  wheat.  In  his  experiment  garden  the 
present  season  one  row  of  these  hybrid  wheats 
was  found  to  have  vitality  that  enabled  it  to  stand 
up  under  drought  and  wind  when  all  the  com- 
panion rows  (representing  different  combina- 
tions) had  wilted. 

It  is  easily  within  the  range  of  the  experiments 
of  any  amateur  to  conduct  similar  tests  in  cross- 
breeding and  selection,  starting  with  standard 
varieties  of  wheat  or  oats  or  rye,  and  working 
with  an  eye  to  the  development  of  hardy  and  un- 
usually productive  varieties.  It  has  been  pointed 
out  that  anyone  who  would  develop  a  race  of 
wheat  that  would  bear  on  the  average  one  kernel 
more  to  the  head  would  thereby  add  millions  of 

[176] 


MR.  BURBANK  PLANTING  CHOICE  SEEDS 

The  seeds  are  being  planted  in  a  box  or  "  flat "  of  the  usual   type. 

The  work  is  being  done  in  the  room  to  the  conservatory.     Note  the  pile 

of   prepared   earth  in    the    background,    and    the    pots    for    transplanting 

seedlings  that  are  to  be  given   special  attention. 


LAWN  AND  DOCKYARD 

bushels  to  the  annual  product,  and  thus  confer  a 
magnificent  benefaction  on  the  race. 

Bear  in  mind  that  the  experiments  necessary 
for  the  development  of  new  varieties  of  cereals 
may  be  made  in  a  plot  of  ground  a  few  feet  square. 
There  is  no  better  use  to  which  you  could  put  one 
or  two  of  the  plots  set  aside  on  your  lawn  for 
ornamental  plants.  The  cereal  grasses  are  grace- 
ful plants,  which,  properly  placed,  would  consti- 
tute a  pleasing  and  novel  feature  of  lawn  decora- 
tion. And  experiments  with  them  might  result  in 
developments  vastly  surpassing  in  importance  all 
other  possibilities  of  your  flower  or  vegetable 
garden. 

It  may  fairly  be  assumed,  however,  that  you 
are  interested  rather  in  the  preparation  of  the 
soil  for  the  lawn  and  in  its  care  than  in  the  im- 
provement of  the  lawn  grasses  proper,  inasmuch 
as  these  have  already  reached  an  advanced  stage 
of  development  at  the  hands  of  numberless  pro- 
fessional gardeners. 

And  as  to  this  aspect  of  the  matter,  Mr.  Bur- 
bank  cites  an  experience  of  his  own  that  is  il- 
luminative, and  may  well  be  narrated.  It  appears 
that  when  he  first  purchased  the  four-acre  plot  of 
ground  at  Santa  Rosa  that  was  afterwards  to  be- 
come so  famous  as  the  seat  of  his  experimental 
labors,  this  land  was  wet  and  soggy  of  soil,  and 
entirely  unproductive.  It  had  been  the  bottom  of 
a  pond  at  some  remote  period,  and  the  soil  re- 
tained an  excess  of  moisture.  Mr.  Burbank's  first 
move  after  purchasing  the  place  was  to  drain  it 

[177] 


LUTHER  BURBANK 

properly.  This  was  accomplished  by  running  a 
main  line  of  four-inch  tiles  down  the  center  of  the 
tract  with  laterals  of  two-inch  tiles  joining  it  at 
right  angles  at  intervals  of  forty  feet.  The  lat- 
erals gather  surplus  water  quickly  after  heavy 
rain,  and  the  main  pipe  carries  it  to  a  small  stream 
nearby.  The  slope  of  the  pipes  is  one  foot  in  forty 
feet. 

THE  WOKLD'S  MOST  PKODUCTIVE  ACEES 

At  first  thought  it  seems  rather  surprising  that 
two-inch  pipes  forty  feet  apart  will  adequately 
drain  a  moist  soil.  But  Mr.  Burbank  points  out 
that  the  drainage  pipes  are  working  day  and 
night,  with  no  rest  on  Sundays,  and  that  they  carry 
a  great  amount  of  water  in  the  course  of  twenty- 
four  hours.  In  point  of  fact,  this  system  of  two- 
inch  laterals  with  a  four-inch  central  pipe  proved 
eminently  satisfactory  at  Santa  Rosa  from  the 
outset,  and  no  change  has  been  necessary  in 
the  thirty  years  it  has  been  in  operation. 
The  pipes  require  no  attention  whatever, — they 
have  never  been  even  inspected  since  they  were 
put  down. 

It  is  of  course  highly  essential  that  each  piece 
of  tiling  as  originally  laid  should  be  perfect,  and 
that  the  entire  system  should  be  carefully  ad- 
justed at  the  proper  grade.  The  joints  should  be 
packed  with  clay.  If  any  part  of  the  line  sags, 
sediment  will  collect  and  retard  the  flow  of  water. 

By  the  mere  installation  of  this  simple  system 

[178] 


LAWN  AND  DOCKYARD 

of  pipes,  the  heavy  adobe  soil  of  Mr.  Burbank's 
Santa  Eosa  place  was  made  arable.  The  soil  was 
then  enriched  by  plowing  in  eighteen  hundred 
loads  of  manure.  Localized  beds  were  subse- 
quently modified  to  meet  the  needs  of  bulbous 
plants  by  mixing  sand  with  the  soil. 

The  net  result  of  this  treatment  was  to  trans- 
form a  tract  that  would  scarcely  support  vegeta- 
tion of  any  kind  into  the  most  productive  four 
acres  perhaps  to  be  found  anywhere  in  the  tem- 
perate zone.  Doubtless  there  is  no  other  tract  of 
similar  size  anywhere  in  the  world  that  has  pro- 
duced so  varied  a  crop  of  vegetation  and  such  pro- 
fusion of  new  and  interesting  and  beautiful  forms 
of  plant  life  year  after  year  as  these  transformed 
acres  at  Santa  Rosa. 

Mr.  Burbank's  experience  affords  a  lesson  by 
which  everyone  who  has  a  small  tract  of  land  that 
he  wishes  to  put  in  condition  for  lawn  or  garden 
may  profit.  Even  if  your  land  lies  in  a  region 
where  there  is  drought  in  summer,  there  are 
periods  of  the  year  when  the  ground  is  unduly 
saturated  with  water,  and  when  it  must  be  drained 
to  permit  the  proper  aeration  of  the  roots  of  the 
plants.  The  drainage  pipes  will  not  take  water 
from  the  soil  except  when  there  is  an  excess  of  it. 
For  dry  soil  absorbs  water  sponge-like  through 
capillarity. 

So,  unless  your  land  is  located  on  a  hillside 
where  there  is  the  best  possible  opportunity  for 
natural  drainage,  you  will  do  well  to  install  a 
system  of  drainage  tiles  like  that  described,  and 

[179] 


LUTHER  BURBANK 

you  may  confidently  expect  that  your  lawn  and 
garden  will  be  noticeably  benefited  thereby. 

As  to  the  preparation  of  the  soil  itself,  every- 
thing depends  upon  the  local  conditions,  and  only 
general  rules  can  be  given.  If  the  soil  is  very 
sandy,  it  will  be  benefited  by  having  clayey  loam 
spread  over  it  and  incorporated  with  it  by  plow- 
ing. And  there  are  very  few  soils  that  are  so 
rich  that  they  will  not  be  benefited  by  thorough 
fertilizing.  For  this  purpose  barnyard  manure 
has  exceptional  value,  not  only  because  it  sup- 
plies plant  foods,  but  also  because  it  gives  the 
right  texture  to  the  soil.  Leaf  mold  from  the 
woods,  if  it  can  be  secured,  has  value  for  the  same 
reason. 

Nowadays  it  is  well  understood  that  the  physical 
texture  of  the  soil  is  almost  as  important  as  its 
chemical  composition.  The  roots  of  the  plants 
require  air  as  well  as  water,  and  they  will  not 
thrive  in  a  soil  that  lacks  porosity.  In  the  garden 
the  soil  is  kept  porous  by  constant  cultivation,  but 
this  is  obviously  not  possible  with  the  lawn ;  hence 
it  is  especially  important  that  soil  for  the  lawn 
shall  have  the  right  texture  before  the  grass  seed 
is  sown. 

SUPPLYING   WATER 

The  lawn  that  needs  to  be  protected  against  an 
excess  of  water  at  one  season  by  a  system  of 
drainage  may  at  another  season  require  artificial 
watering  even  more  imperatively.  The  question 

[180] 


LAWN  AND  DOCKYARD 

of  artificial  irrigation  is  therefore  no  less  impor- 
tant than  that  of  artificial  drainage. 

Here  again  the  needs  of  the  lawn  call  for  special 
consideration,  both  because  the  soil  cannot  be  kept 
porous  by  cultivation  and  because  the  roots  of 
the  grass  permeate  the  entire  surface  and  exhaust 
the  water  supply  very  rapidly.  The  fault  with 
most  of  the  common  sprinklers  used  to  irrigate 
lawns  and  small  gardens,  says  Mr.  Burbank,  is 
that  they  do  not  distribute  the  water  evenly.  Most 
of  them  cover  a  circular  space,  and  there  is  always 
some  part  of  the  soil  which  has  too  much  water 
while  other  parts  have  too  little.  One  of  the  most 
important  points  in  irrigation  is  to  have  the  water 
distributed  evenly. 

Some  of  the  flat  or  fishtail  sprinklers  distribute 
the  water  better  than  the  older  forms,  but  Mr. 
Burbank  especially  commends  the  newer  system 
of  overhead  irrigation  as  far  superior  to  the  old 
forms  of  sprinkling.  He  recommends  the  use  of 
a  number  of  one-inch  galvanized  pipes  with  noz- 
zles placed  along  the  sides  from  twelve  to  twenty 
inches  apart.  The  pipes,  mounted  on  stakes  at 
a  convenient  height,  are  connected  with  the  water 
supply  by  ordinary  rubber  hose.  A  single  system 
of  pipes  will  water  a  space  evenly  to  a  distance  of 
from  twenty-five  to  fifty  feet  on  either  side.  Thus 
an  ordinary  lawn  may  be  supplied  from  a  line  of 
pipes  at  either  side,  and  these  pipes  may  be  con- 
cealed by  a  trellis  of  ornamental  vines. 

The  system  may  be  so  modified  that  the  pipes 
instead  of  being  held  on  permanent  stakes  are  car- 

[181] 


LUTHER  BURBANK 

ried  from  one  place  to  another  and  placed  on  tem- 
porary stakes  or  movable  stands. 

A  modification  of  the  system  is  to  have  the  pipes 
underground,  just  at  the  surface.  This  has  the 
advantage  of  having  the  pipes  out  of  sight,  but 
the  system  is  more  costly  to  install.  The  fact  that 
the  iron  pipes  last  for  many  years  should  be  taken 
into  account,  however.  The  part  of  the  ordinary 
sprinkling  system  that  deteriorates  most  rapidly 
is  the  rubber  hose.  The  permanency  of  the  iron 
pipe  system  soon  compensates  for  the  initial  cost. 
Moreover,  the  saving  in  both  time  and  water  is 
notable,  and  the  lawn  is  given  a  much  more  evenly 
distributed  supply  of  moisture. 

The  same  system  may  advantageously  be  util- 
ized in  the  flower  garden  and  vegetable  garden. 
A  single  line  of  pipe  may  be  arranged  so  that  it 
will  water  the  beds  on  either  side.  Where  the 
prevailing  winds  come  from  one  direction  through- 
out the  summer,  it  is  advantageous  to  place  the 
irrigating  pipe  on  the  windward  side  of  the  lawn 
or  garden  to  gain  the  aid  of  the  wind  in  spraying 
the  water  over  a  wider  surface. 

OENAMENTAL  FLOWEE   BEDS 

There  are  few  other  lines  of  plant  experiment 
to  which  Mr.  Burbank  has  given  greater  attention 
than  that  having  to  do  with  the  production  of 
ornamental  flowers  adapted  for  massed  display 
in  beds  on  the  lawn  or  in  the  dooryard. 

He  has  introduced,  for  example,  half  a  dozen 
[182] 


LAWN  AND  DOCKYARD 

new  forms  of  callas,  including  varieties  with 
spotted  leaves  that  have  a  peculiarly  striking 
massed  effect;  a  dozen  new  dahlias  of  the  most 
varied  and  beautiful  forms  and  colors  (among 
others,  the  first  fully  double  ones,  and  a  fragrant 
variety) ;  more  than  twenty  new  gladioli  of  rare 
beauty;  a  large  number  of  poppies  of  the  most 
exquisite  quality  of  petal  and  of  rare  colors ;  and 
numerous  roses  that  reveal  an  unmistakable  Bur- 
bank  quality.  Then,  too,  there  are  cannas,  ver- 
benas, larkspurs,  myrtles,  codetias,  lobelias, 
pentstemons,  eriophyllums,  firecracker  flowers, 
primroses,  and  the  wonderful  giant  amaryllis, 
with  a  coterie  of  exotic  forms  of  less  familiar 
name,  on  the  one  hand,  and  perfected  varieties  of 
such  familiar  flowers  as  the  milkweed  and  iris 
and  petunia  and  bleeding-heart  and  goldenrod,  on 
the  other. 

All  of  these  have  been  brought  under  Mr.  Bur- 
bank's  tutorage,  and  have  been  made  to  reveal 
new  possibilities  of  development  of  form  or  color 
or  fragrance  or  profuseness  of  bearing.  The  ex- 
periment gardens  at  Santa  Rosa  and  Sebastopol 
are  objects  of  admiring  attention  to  hundreds  of 
visitors  throughout  the  season,  and  the  new  forms 
of  flowers  here  developed  are  sent  out  to  gladden 
the  hearts  of  flower  lovers  everywhere  in  the 
world. 

However  varied  the  qualities  of  the  different 
flowers,  the  same  general  principles  of  develop- 
ment apply  to  all  of  them.  Hybridization  and  se- 
lection are  the  keys  to  progress  and  plant  develop- 

[183] 


LUTHER  BURBANK 

ment,  whether  we  deal  with  gladiolus  or  with 
canna,  with  dahlia  or  with  petunia,  with  mallow 
or  with  amaryllis.  There  are  important  details 
of  difference,  however,  some  of  which  will  be  out- 
lined in  a  moment. 

There  is  no  reason  why  you  should  not  improve 
upon  any  one  of  the  flowers  that  ornament  your 
lawn  or  dooryard.  By  applying  your  own  taste 
in  the  selection  of  plants  whose  seeds  shall  be 
preserved,  you  may  put  the  imprint  of  your  own 
personality  on  new  varieties,  just  as  Mr.  Burbank 
has  put  the  imprint  of  his  personality  on  the 
varieties  that  are  now  sent  out  from  Santa  Rosa. 

Perhaps  it  may  not  have  occurred  to  you,  but  it 
is  nevertheless  true,  that  the  Burbank  flowers 
have  delicacy  and  artistic  quality  of  form,  and 
harmonious  blending  of  color,  and  exquisite  per- 
fume because  Mr.  Burbank  himself  is  a  man  of 
refined  sensibilities  to  whom  these  qualities  ap- 
peal. By  the  same  token,  you  may  develop,  if 
you  so  elect,  in  the  course  of  two  or  three  seasons, 
new  varieties  of  flowers  that  will  represent  your 
personality  quite  as  fully  as  you  are  represented 
by  your  costume  or  the  equipment  of  your  bou- 
doir. To  have  a  flower  garden  of  such  unique 
individuality  is  surely  a  worthy  ambition ;  and  it 
is  one  that  may  readily  be  gratified. 

IMPKOVING   THE   GLADIOLUS 

As  illustrating  the  possibility  of  doing  remark- 
able work  with  a  very  common  plant,  it  is  worth 

[184] 


A  BURBANK  HYBRID  TIGRIDIA. 

This  is  one  of  many  interesting  varieties  of  Hybrid  Tigridia  that 
Mr.  Burbank  has  developed.  The  plants  are  spotted  and  not  striped, 
yet  there  does  seem  to  be  something  tiger-like  about  this  richly 
caparisoned  and  oriental-seeming  specimen.  It  is  rather  curious  to 
reflect  that  the  spots  on  the  flower  are  intended  to  make  it  con- 
spicuous, whereas  the  striped  coat  of  its  namesake  is  calculated  to 
make  the  animal  invisible  in  the  jungle. 


LAWN  AND  DOCKYARD 

while  to  recall  details  already  given  as  to  Mr. 
Burbank  rs  work  with  the  gladiolus.  He  has 
worked  with  many  varieties,  and  has  raised  the 
bulbs  by  hundreds  of  thousands;  and  there  is 
scarcely  a  quality  of  bulb  or  stalk  or  flower  that  he 
has  not  modified  in  one  direction  or  another. 

The  bulbs  have  been  made  to  produce  bulblets 
rapidly;  they  have  been  rendered  hardy;  and  in 
particular  they  have  been  made  relatively  immune 
to  disease.  The  stalks  have  been  caused  to  grow 
to  gigantic  size,  and  to  bear  flowers  not  merely  on 
one  side,  as  they  were  formerly  wont  to  do,  but  in 
spirals  that  showed  the  flowers  in  a  solid  cluster, 
the  blossoms  facing  in  all  directions.  The  flowers 
themselves  have  been  very  markedly  increased  in 
size,  and  given  brilliancy  of  coloration  and  re- 
markable keeping  quality. 

Mr.  Burbank  says  that  the  possibilities  in  ex- 
perimenting with  color  in  the  gladiolus  rival  the 
experiments  that  a  painter  makes  with  the  pig- 
ments of  his  palette.  Mr.  Burbank  himself  has 
a  remarkable  color  sense,  and  he  takes  particular 
delight  in  modifying  the  shades  of  color  of  his 
flower  creations,  and  enhancing  their  delicacy  and 
beauty.  He  has  found  that  certain  combinations 
of  colors  can  be  made,  quite  as  in  the  case  of  the 
artist's  pigments,  with  pleasing  results,  and  that 
other  combinations  should  be  avoided.  If  a  pink 
gladiolus,  for  example,  is  combined  with  a  white 
one,  the  result  will  probably  be  a  paler  pink  that 
is  not  pleasing.  On  the  other  hand,  it  was  by 
combining  a  small  purplish  gladiolus,  imported 

[185] 


LUTHER  BURBANK 

from  Europe,  with  a  white  one  that  Mr.  Burbank 
produced  his  remarkable  blue  gladiolus.  Flower 
lovers  are  aware  that  the  gladiolus,  like  the  poppy 
and  rose,  is  not  partial  to  the  color  blue.  Yet  Mr. 
Burbank  has  succeeded,  after  a  long  term  of 
experimentation,  in  developing  a  blue  strain  of 
gladiolus  that  is  as  beautiful  as  it  is  unusual. 

Mention  has  been  made  of  the  white  gladiolus, 
but  it  should  be  explained  that  this  flower  is  not 
pure  white,  as  comparison  with  a  white  watsonia 
flower  will  show.  The  white  of  the  watsonia  has 
been  termed  "the  whitest  white  in  nature."  It  is 
of  interest  to  recall  that  the  progenitor  of  the 
white  watsonia  was  a  "sport"  found  in  the  native 
home  of  the  plant,  South  Africa,  in  a  region  where 
watsonias  of  the  normal  reddish  color  were 
abundant.  The  white  sport  bred  true,  and  it  was 
presently  introduced  in  the  gardens  of  Europe 
and  America. 

Unfortunately,  the  watsonia  is  a  rather  tender 
plant,  and  this  has  interfered  with  its  popularity 
in  the  eastern  United  States.  Yet  it  is  a  plant 
worthy  of  cultivation,  and  one  that  in  many  ways 
rivals  the  gladiolus,  which  it  somewhat  resembles. 
It  has  been  a  favorite  flower  with  Mr.  Burbank, 
who,  besides  improving  it  in  many  features  of 
bulb  and  stalk,  has  devoted  particular  attention 
to  the  development  of  its  color  possibilities.  By 
combining  the  white  and  red  strains,  and  making 
various  recombinations  of  the  offspring  through 
many  generations,  and  by  rigid  selection  among 
the  flowers  showing  slight  variation,  he  has  devel- 

[186] 


LAWN  AND  DOCKYARD 

oped  watsonias  of  multiform  colors,  some  of  which 
show  delicate  shades  of  purple  and  pink  that  are 
rivaled  only  by  the  orchids. 

THE  EOTATION   OF   CHOPS 

In  his  work  with  the  bulbous  plants,  Mr.  Bur- 
bank  has  met  with  peculiar  difficulties  because 
from  time  to  time  his  fields  have  been  invaded  by 
a  pestiferous  little  mammal,  the  pocket  gopher, 
which  burrows  underground,  and  which  has  on 
occasion  destroyed  thousands  of  his  choicest  bulbs 
before  the  presence  of  the  marauder  was  detected. 
'At  one  time  the  gophers  became  so  destructive — 
seeming  always,  as  Mr.  Burbank  says,  to  select 
his  choicest  bulbs — that  the  plant  breeder  was  led 
to  give  up  the  cultivation  of  the  gladiolus  and  of 
various  allied  bulbous  plants.  Only  after  almost 
numberless  experiments  did  he  find  a  method  of 
coping  with  the  rodents. 

The  successful  device  was  a  kind  of  gun  that 
is  exploded  just  at  the  moment  when  the  body  of 
the  gopher  is  in  contact  with  a  quantity  of  powder. 
After  this  device  was  in  hand,  Mr.  Burbank  re- 
turned to  the  interrupted  line  of  experiments  with 
the  bulbs,  and  his  experiments  with  plants  of  this 
character  have  been  among  his  most  important 
works  of  recent  years. 

In  carrying  out  these  experiments  on  an  ex- 
tensive scale,  he  has  discovered  that  there  are 
other  pests  that  are  almost  as  destructive  as  the 
gopher.  The  bulbous  plants,  indeed,  are  pecul- 

[187] 


LUTHER  BURBANK 

iarly  subject  to  the  attacks  of  various  fungous 
and  insect  foes.  It  is  in  the  endeavor  to  ward 
off  these  foes  that  most  bulbs  have  developed  a 
bitter  principle.  In  many  cases,  however,  the  in- 
sects refuse  to  be  discouraged  by  the  bitter  taste, 
and  eat  the  bulbs  with  avidity,  often  working  de- 
struction to  the  choicest  specimens,  and  making 
progress  impossible. 

To  guard  against  such  mishaps,  Mr.  Burbank 
recommends  that  any  soil  in  which  bulbous  plants 
are  grown  should,  if  possible,  be  thoroughly 
sterilized  before  the  bulbs  are  set  out.  Where  the 
quantity  is  small,  it  may  be  possible  to  dig  up  the 
soil  and  sterilize  it  by  baking.  When  this  is  im- 
possible, something  may  be  accomplished  by  the 
use  of  germicides.  In  recent  years  Mr.  Burbank 
has  used  large  quantities  of  a  liquid  preparation 
known  as  tuolene,  and  he  regards  this  as  the  best 
germicide  that  he  has  ever  used. 

By  impregnating  the  soil  with  this  solution, 
protection  is  given  the  delicate  bulbous  plants, 
and  they  may  thrive  where,  if  not  given  such  aid, 
they  would  inevitably  have  perished. 

It  is  impossible,  however,  to  rid  the  soil  per- 
manently of  all  fungous  and  insect  intruders. 
Where  bulbs  are  grown  in  the  same  soil,  in  suc- 
cessive seasons,  these  enemies  are  sure  to  accumu- 
late. Moreover,  the  roots  of  plants  may  give  out 
excretions  that  render  the  soil  noxious  for  that 
particular  species.  Therefore,  Mr.  Burbank  es- 
pecially recommends  that  anyone  having  to  do 
with  bulbous  plants  should  change  the  location 

[188] 


LAWN  AND  DOCKYARD 

year  by  year,  never  having  the  same  bulbs  in  a 
bed  two  years  in  succession.  It  is  better,  indeed, 
not  to  raise  plants  of  any  one  kind  for  successive 
seasons  in  a  bed,  but  to  alternate  between  bulbous 
plants  and  annuals  grown  from  the  seed.  Failure 
to  carry  out  such  a  rotation  of  crops  is  a  very 
common  source  of  failure  with  the  amateur  gar- 
dener. It  is  not  at  all  unusual  to  see  an  amateur 
obtain  excellent  results  for  one  or  two  seasons, 
and  then  to  have  her  garden  degenerate  simply 
because  she  has  attempted  to  raise  the  same  kind 
of  plant  year  after  year  in  the  same  location.  By 
transposing  the  different  plants — putting  the 
gladioli  this  year  where  petunias,  for  example, 
were  grown  last  year,  and  the  like — all  the  plants 
may  be  kept  in  vigorous  growth.  Attention  to  this 
detail  may  make  all  the  difference  between  suc- 
cess and  failure  in  the  disposition  of  flower  beds 
to  ornament  the  dooryard. 

If  it  is  your  desire  to  keep  bulbous  plants  year 
after  year  in  the  same  bed,  you  may  accomplish 
this  if  you  are  willing  to  take  the  trouble  to  dig 
out  the  top  soil  and  pile  it  up  in  some  out-of-the- 
way  corner  and  replace  it  with  other  soil,  which 
will  in  turn  be  dug  up  and  piled  for  renovation 
next  season.  After  lying  in  a  heap  exposed  to 
air  and  sun  for  a  season,  the  dirt  becomes  thor- 
oughly sterilized,  and  may  be  restored  for  use  the 
ensuing  year. 

In  other  words,  you  may  have  two  coats  of 
soil  for  your  flower  bed,  to  use  in  alternate 
seasons. 

[189] 


LUTHER  BURBANK 

Mr.  Burbank  does  not  employ  this  method,  as 
he  works  on  too  comprehensive  a  scale,  but  it  is 
used  by  Professor  Hugo  De  Vries,  the  celebrated 
Amsterdam  botanist.  In  his  experiment  gardens 
at  Amsterdam,  you  may  see  heaps  of  dirt  being 
thus  renovated  with  the  aid  of  time  and  the  ele- 
ments, and  any  amateur  who  operates  on  a  small 
scale  may  imitate  the  example. 

Ordinarily,  of  course,  it  will  be  more  expedient 
to  practice  rotation  of  crops,  giving  your  soil  the 
additional  benefit  of  occasional  sprinkling  with 
a  germicide.  But  for  the  benefit  of  the  small  beds 
located  in  some  particular  part  of  the  lawn  where 
you  wish,  for  example,  to  keep  cannas  or  gladioli 
or  tulips  season  after  season,  the  more  trouble- 
some but  highly  effective  method  of  using  two 
coatings  of  soil  in  alternate  years  may  be  worthy 
of  consideration. 

SOME   GIGANTIC   FLOWEBS 

Among  Mr.  Burbank 's  almost  endless  experi- 
ments with  bulbous  plants,  perhaps  none  have 
greater  interest  than  those  that  have  to  do  with 
the  not  very  familiar  plants  which  are  known  to 
the  horticulturist  under  the  name  of  Amaryllis, 
but  which  really  belong  to  several  somewhat 
closely  allied  genera.  One  true  amaryllis  (the 
so-called  belladonna  lily)  is  a  rather  common 
plant  indigenous  to  the  United  States.  But  the 
plants  that  go  by  the  name  in  horticultural  circles 
are  mostly  of  the  genus  Hippeastrum,  and  have 

[190] 


LAWN  AND  DOCKYARD 

been  brought  to  us  from  the  tropics.  There  are 
also  the  allied  genera  of  Crinum  and  Sprekelia. 

Mr.  Burbank  has  hybridized  these  plants  in  a 
great  number  of  combinations,  and  has  produced 
some  very  striking  and  remarkable  results. 

His  work  with  the  plants  of  the  genus  Eip- 
peastrum — making  up  the  body  of  the  flowers  usu- 
ally termed  amaryllis — has  had  to  do  with  a  num- 
ber of  species  that  have  been  long  under  cultiva- 
tion, including  some  that  have  been  earlier  hy- 
bridized, as  well  as  with  less  familiar  species  im- 
ported from  tropical  regions. 

At  first  Mr.  Burbank  had  difficulty  in  hybrid- 
izing these  plants,  but  he  presently  discovered  that 
the  difficulty  lay  solely  in  the  selection  of  just  the 
right  time  to  apply  the  pollen.  The  pistil  does  not 
become  mature  until  after  the  pollen  of  the  same 
flower  has  been  discharged.  By  bearing  this  in 
mind,  and  gathering  pollen  on  a  watch  crystal,  if 
necessary,  to  await  the  maturing  of  the  pistil  of 
another  flower,  cross-fertilization  presents  no  dif- 
ficulties. By  working  for  twelve  or  fifteen  suc- 
cessive seasons,  Mr.  Burbank  produced  complex 
hybrids  that  are  really  very  remarkable  plants. 
Some  of  them  have  enormous  bulbs,  with  a  pro- 
pensity to  produce  bulblets  at  a  really  astonish- 
ing rate. 

Many  varieties  of  amaryllis  produce  only  one 
or  two  bulbs  in  a  season,  which  accounts  for  the 
fact  that  these  bulbs  are  costly.  But  Mr.  Burbank 
so  stimulated  the  bulb-producing  capacity  of  his 
hybrid  varieties  that  his  most  prolific  species  will 

[191] 


LUTHER  BURBANK 

produce  a  new  bulb  every  week,  or  fifty  new  bulbs 
in  a  year. 

In  point  of  prolific  bearing,  there  was  cor- 
responding progress.  Not  only  do  the  hybrid  spe- 
cies produce  large  stalks,  but  they  produce  four 
or  five  stalks  to  a  bulb,  instead  of  the  original 
two  or  three,  and  sometimes  as  many  as  twelve 
flowers  to  the  stem  (when  they  have  remained  in 
the  ground  for  a  few  seasons),  instead  of  the 
original  four  or  five  flowers  in  a  cluster.  The  en- 
hanced fecundity  of  the  new  forms  is  supple- 
mented by  their  tendency  to  early  bearing.  They 
will  sometimes  bloom  the  second  year  from  seed, 
and  on  the  average  they  bloom  in  three  or  four 
years;  whereas  the  old  forms  sometimes  required 
six  or  eight  years  to  come  to  maturity.  Thus 
Mr.  Burbank  has  pretty  nearly  cut  in  half  the 
time  from  seed  to  blossom  in  the  amaryllis.  Hy- 
bridization and  selective  breeding  are  of  course 
the  magic  methods  that  accomplish  these  results. 

But  the  most  spectacular  transformation  has 
to  do  with  the  flowers  themselves.  In  the  original 
species,  the  largest  flower  seldom  attained  a  diam- 
eter of  more  than  five  or  six  inches.  Mr.  Bur- 
bank's  hybrid  species  of  giant  amaryllis  produce 
flowers  that  are  almost  a  foot  in  diameter. 

These  megaphone-like  flowers  of  the  giant 
amaryllis  are  among  the  most  striking,  as  well  as 
among  the  most  beautiful,  objects  to  be  seen  in 
Mr.  Burbank 's  experiment  gardens. 

It  should  be  added  that  the  giant  amaryllis  does 
not  produce  its  largest  flowers  until  it  has  at- 

[192] 


LAWN  AND  DOORYARD 

tained  full  maturity.  The  flowers  may  increase 
in  size  for  several  successive  seasons  as  the  bulb 
gains  size  and  strength. 

Moreover,  it  is  necessary  to  give  the  bulbs  good 
treatment — rich  soil,  plenty  of  water  and  sunlight 
— in  order  to  have  them  reveal  their  full  possi- 
bilities. In  particular,  Mr.  Burbank  points  out 
that  a  bulb  that  has  been  ill-treated  in  its  first 
season  will  never  produce  a  large  flower,  even 
though  it  have  the  hereditary  factors  for  large 
blooming. 

The  amount  of  patient  work  required  to  secure 
just  the  right  combinations  will  be  appreciated 
when  it  is  said  that  Mr.  Burbank  experimented 
for  about  fourteen  years  before  obtaining  varie- 
ties of  amaryllis  that  seemed  worthy  of  intro- 
duction. 

I  had  an  illustration  of  the  precocity  of  some 
of  these  plants  when  an  amaryllis  bulb  brought 
from  Santa  Rosa  and  potted  indoors  in  New  York 
in  the  month  of  April  sent  up  a  flower  stalk  and 
put  forth  the  first  of  a  series  of  beautiful  blos- 
soms in  the  extraordinary  short  space  of  eight 
days. 

ENORMOUS   BULBS   OF   HYBEID   CRINUM   AND 
AMAEYLLIS 

Mr.  Burbank  has  crossed  the  true  amaryllis 
with  plants  of  the  genus  Crinum  with  spectacular 
results. 

Some  of  the  hybrids  have  enormous  bulbs, — 
[193] 


LUTHER  BURBANK 

far  larger  than  a  man's  head, — and  their  flowers 
seem  intermediate  in  character  between  those  of 
the  parents.  But  the  two  plants  are  evidently 
pretty  nearly  at  the  limits  of  affinity,  and  while 
the  hybrids  put  forth  flowers  abundantly,  they  do 
not  have  viable  seeds. 

Of  course  the  new  plants  may  be  propagated 
indefinitely  from  bulbs,  so  that  the  hybrid  crinums 
constitute  interesting  permanent  varieties.  But 
the  experiment  cannot  be  carried  beyond  the  first 
generation  because  the  hybrids  are  sterile.  Such, 
at  least,  has  been  Mr.  Burbank's  experience.  It  is 
quite  possible,  however,  that  it  may  be  feasible  to 
find  species  of  crinums  or  individual  flowers  that 
would  produce  fertile  offspring  when  crossed  with 
the  amaryllis.  At  least  further  experimentation 
along  this  line  is  worth  making. 

It  would  also  be  of  interest  to  attempt  to  cross 
the  crinums  with  the  hippeastrum  or  tropical 
amaryllis,  a  combination  that  Mr.  Burbank  has 
attempted  many  times,  but  hitherto  without 
success. 

All  in  all,  the  plants  of  the  amaryllis  tribe  fur- 
nish rare  opportunities  for  experiment  in  the 
hands  of  the  amateur,  particularly  since  Mr.  Bur- 
bank  has  developed  species  that  are  sufficiently 
hardy  to  thrive  out  of  doors  in  our  northern  lati- 
tudes. A  good  deal  of  patience  is  required,  to 
be  sure,  in  awaiting  the  maturation  of  the  flowers ; 
but  experiments  in  cross-pollenation  may  be  begun 
without  delay,  if  you  start  with  mature  bulbs. 
The  pollenizing  of  the  flowers  presents  no  difficul- 

[194] 


LAWN  AND  DOCKYARD 

ties  whatever,  if  care  is  taken  to  apply  the  pollen 
to  the  pistil  when  it  is  fully  mature. 

To  make  sure  of  this  it  is  well  to  apply  the 
pollen  on  several  successive  days.  With  some  spe- 
cies the  maturing  of  the  pistil  is  marked  by  its 
curving  upward;  in  others  it  elongates  rapidly, 
the  result  in  either  case  being  to  place  the  pistil 
where  it  will  be  likely  to  receive  pollen  from  the 
large  moths  or  the  humming-birds  that  ordinarily 
fertilize  tubular  blossoms  of  this  type. 

WORKING   WITH   THE   RESPONSIVE   DAHLIA 

Apropos  of  the  pollenizing,  it  may  be  well  to 
call  attention  to  difficulties  that  confront  the 
worker  when  he  deals  with  the  composite  flowers, 
of  which  the  various  sunflowers  and  the  dahlia 
furnish  familiar  examples.  The  peculiarity  of  the 
composite  flower,  it  will  be  recalled,  is  that  a  large 
number  of  blossoms  are  gathered  in  a  single  head, 
about  which  a  conspicuous  circle  of  ray  flowers  or 
florets  is  displayed. 

This  is  an  example  of  communism  in  the  plant 
world,  as  a  single  circle  of  petal-like  appendages 
is  made  to  serve  as  an  advertisement  to  insects 
for  all  the  numerous  blossoms  of  the  cluster, 
whereas  ordinary  flowers  have  a  set  of  petals  for 
each  individual  blossom.  But  whereas  this  ar- 
rangement is  eminently  satisfactory  from  the 
standpoint  of  the  plant  itself,  the  grouping  of 
flowers  in  a  mass  obviously  complicates  the  prob- 
lem of  the  hand  pollenizer. 

[195] 


LUTHER  BURBANK 

The  best  practical  method  in  eross-pollenizing 
composite  flowers — for  example,  dahlias — is  to 
wash  away  with  a  spray  of  water  the  pollen  of 
the  flower  head  that  is  to  be  fertilized,  afterwards 
rubbing  its  surface  gently  with  the  pollenizing 
head  plucked  from  another  plant.  Of  course  you 
cannot  always  be  sure  that  the  flowers  have  not 
been  fertilized  by  pollen  from  other  florets  in  the 
same  head  before  you  began  operations.  More- 
over, as  the  flowers  of  the  head  do  not  mature 
all  at  the  same  time,  but  gradually  ripen  from  cir- 
cumference to  center,  you  must  repeat  the  opera- 
tion on  several  successive  days  to  make  sure  of 
hybridizing  a  large  proportion  of  the  blossoms  in 
a  given  head. 

At  best  there  will  be  an  element  of  uncertainty 
about  the  result,  but  this  will  give  additional  zest 
to  the  experiment  and  increase  the  interest  with 
which  you  will  await  the  blossoming  next  season 
of  the  plants  grown  from  the  seeds  of  a  flower 
head  thus  manipulated. 

The  dahlia  furnishes  perhaps  the  best  example 
of  a  familiar  composite  flower  with  which  you  may 
begin  your  experiments  in  this  somewhat  more 
difficult  type  of  cross-pollenizing.  As  these  flow- 
ers are  at  their  best  late  in  the  fall,  there  is  still 
abundant  opportunity  for  work  during  the  present 
season.  And  notwithstanding  the  large  amount 
of  work  that  has  been  done  with  the  dahlia,  you 
may  hope  to  secure  very  interesting  new  devel- 
opments. 

Mr.  Burbank  has  worked  very  extensively  with 
[196] 


LAWN  AND  DOCKYARD 

this  group  of  flowers,  and  has  produced  some  very 
striking  hybrids  by  combining  the  familiar  garden 
species  with  wild  species  brought  from  Mexico. 
You  may  secure  a  sufficient  variety  of  dahlias 
from  any  florist  to  give  ample  opportunity  for 
further  hybridizing  experiments.  No  dooryafd 
would  be  complete  in  its  autumnal  floral  display 
that  did  not  have  a  bed  or  two  of  these  very  at- 
tractive flowers. 

The  wild  progenitors  of  the  modern  races  of 
dahlias  have  flowers  with  a  single  row  of  florets, 
like  the  wild  sunflowers.  The  complex  rounded 
heads  of  many  cultivated  varieties  are  due  to  the 
transformation  of  the  minute  and  originally  incon- 
spicuous florets  of  the  cluster  under  the  stimula- 
tive influences  of  changed  environment  and  arti- 
ficial cultivation. 

To  observe  the  contrast  between  the  wild  dah- 
lia and  its  cultivated  descendant  is  to  receive  a 
vivid  object  lesson  in  the  possibilities  of  flower 
development. 

Even  without  hybridizing,  you  may  develop  a 
great  variety  of  dahlias.  All  the  varieties  under 
cultivation  are  complex  in  their  heritage,  and  the 
fact  that  the  plants  may  be  multiplied  by  division 
has  made  it  unnecessary  to  carry  selective  breed- 
ing to  the  stage  of  fixing  qualities  so  that  plants 
grown  from  the  seed  will  reproduce  in  detail  the 
features  of  their  parent  plants. 

You  may  find  endless  amusement  and  interest 
in  selecting  new  varieties  from  among  the  plants 
grown  from  a  single  packet  of  seeds,  and  you  may 

[197] 


LUTHER  BURBANK 

try  your  hand  at  fixing  new  types  by  careful  in- 
breeding and  further  selection.  A  very  interest- 
ing experiment  may  be  made  by  planting  all  the 
seeds  from  a  single  dahlia  head  in  separate  plots ; 
carefully  screening  each  plant  against  cross- 
pollenation,  and  noting  results  in  the  second  filial 
generation.  Each  seed  may  seem  to  give  a  unique 
variety,  and  by  persistent  selection  through  sev- 
eral generations,  following  the  same  method,  you 
may  secure  an  endless  variety  of  interesting  types. 
Meantime,  any  individual  that  you  prize  may 
serve  as  the  progenitor,  through  root  division,  of 
an  entire  race  exactly  like  itself. 

STUDIES  IN    COLOR   VARIATION" 

The  dahlia  also  offers  large  possibilities  for  the 
study  of  color  variation,  and  for  experiment  in 
the  blending  of  different  colors  to  produce  new 
types.  As  illustrating  the  possibilities  of  develop- 
ment of  this  flower,  it  may  be  recalled  that  this 
is  one  of  the  most  recent  acquisitions  in  the  flower 
garden,  the  dahlia  having  been  brought  under  cul- 
tivation only  four  or  five  human  generations  ago. 

The  species  of  dahlia  first  introduced  from 
Mexico  was  brought  to  England  in  the  year  1789 
by  the  Marchioness  of  Butte.  It  had  the  general 
form  of  a  very  large  daisy,  and  it  resembled 
numerous  familiar  wild  sunflower-like  composites, 
except  that  its  floral  envelope  was  dull  scarlet  with 
a  yellow  center.  Subsequently  other  species  were 
introduced,  and  through  hybridization  and  selec- 

[198] 


LAWN  AND  DOCKYARD 

tion  the  flower  was  not  only  made  to  take  on  the 
greatly  modified  form  with  which  we  are  familiar, 
but  its  color  scheme  was  indefinitely  modified,  al- 
though the  original  red  and  yellow,  together  with 
the  white  and  crimson  of  certain  other  species, 
form  the  basis  of  coloration  of  all  the  cultivated 
varieties.  Almost  any  of  these  show  sufficient 
diversity  of  color  to  make  interesting  experiments 
in  blending  and  modifying  their  color  scheme 
feasible. 

Equally  interesting  studies  of  color  variation 
may  be  made  with  the  different  types  of  roses. 
Added  zest  is  given  to  these  experiments  by  the 
fact  that  many  of  the  roses  are  not  readily  cross- 
fertilized.  Mr.  Burbank  tells  us,  for  example,  that 
he  has  grown  upward  of  two  hundred  thousand 
seedlings  from  the  crimson  rambler  pollenated 
with  all  the  ordinary  roses  that  are  under  culti- 
vation in  California.  He  found  that  the  pollen 
of  only  a  few  roses  proved  effective.  Here  and 
there  a  rose  like  the  Empress  of  India  or  the 
Cecil  Bruner  would  pollenize  readily  with  the 
rambler,  and  the  hybrid  progeny  would  sometimes 
cross  readily  with  numerous  other  hybridized 
roses  with  which  the  crimson  rambler  itself  could 
be  united  with  difficulty,  or  not  at  all.  Under 
these  conditions,  it  is  obvious  that  the  hybrids 
soon  become  very  complex  as  to  their  ancestry, 
and  the  sorting  out  and  isolation  of  their  heredi- 
tary factors  in  new  combinations  may  become  a 
fascinating  puzzle. 

Still  another  familiar  flower  with  which  work 
[199] 


LUTHER  BUKBANK 

in  color  variation  may  readily  be  carried  out  is 
the  verbena.' '  The  ancestors  of  the  cultivated  ver- 
bena were  South  American  plants,  and  it  is  be- 
lieved that  there  are  four  chief  species  that  have 
been  variously  hybridized  to  produce  all  the  forms 
now  under  cultivation.  One  of  the  original  species 
bears  flowers  of  brilliant  red,  two  others  have 
flowers  that  are  rosy  or  purple  in  color,  and  the 
flowers  of  the  fourth  are  pure  white.77 

The  hybridized  races  show  the  breaking  up  of 
these  colors,  quite  as  might  be  expected,  with  a 
presentation  of  all  the  primary  colors  in  many  of 
their  hues  and  gradations,  although  pure  blues  are 
not  well  represented,  and  pure  yellow  is  very  ex- 
ceptional. To  experiment  in  the  production  of 
new  colors  and  combination  of  colors,  it  is  not 
necessary  to  hybridize  the  verbenas,  as  few  if  any 
of  the  familiar  forms  breed  true  from  the  seed. 
((  You  may  secure  all  the  variation  that  is  desirable 
among  the  plants  grown  from  a  single  packet  of 
seeds,  and  may  isolate  and  fix  by  selection  an  in- 
definite number  of  new  types  with  color  schemes 
that  please  your  eye.  It  is  possible,  also,  that  you 
may  find  among  your  verbenas  an  exceptional 
flower  with  a  pleasing  odor,  and  this  also  may 
serve  as  the  basis  for  an  interesting  series  of  ex- 
periments in  selective  breeding.  Through  such  an 
accidental  discovery,  Mr.  Burbank  was  able  to  de- 
velop two  varieties  of  fragrant  verbenas  which 
were  introduced  under  the  names  of  the  May- 
flower and  the  Elegance. 

<A  In  each  case  the  plant  from  which  the  fragrant 

[200] 


LAWN  AND  DOCKYARD 

race  was  developed  was  found  among  thousands 
of  companion  seedlings,  most  of  which,  as  is  usual 
with  the  cultivated  varieties,  had  a  rather  dis- 
agreeable odor.  A  large  number  of  races  of 
fragrant  verbenas  have  been  developed  from  the 
two  that  Mr.  Burbank  isolated  in  his  garden. 

The  explanation  of  the  appearance  now  and 
then  of  a  verbena  with  a  pleasing  odor  is  found  in 
the  fact  that  one  of  the  original  wild  species  the 
strains  of  which  have  been  blended  to  produce 
the  cultivated  varieties  has  a  rich  jasmine  fra- 
grance. The  early  cultivators,  giving  heed  to  the 
color  and  form  of  their  hybrid  plants,  ignored  the 
matter  of  fragrance,  so  the  verbena  developed 
wonderfully  symmetrical  clusters,  and  its  flowers 
took  on  the  most  gaudy  hues,  but  these  handsome 
blossoms  were  of  rather  disagreeable  odor  until 
the  submerged  quality  of  fragrance  was  brought 
out — the  coveted  qualities  of  form  and  color  being 
retained — by  selective  line  breeding. 

OENAMENTAL   SHEUBS  AND   VINES 

It  is  not  necessary  to  speak  in  detail  of  the 
other  familiar  border  and  bed  flowers — salvias, 
petunias,  geraniums,  roses,  and  the  rest — that  are 
everywhere  available  for  the  ornamentation  of 
lawn  and  dooryard.  The  selection  and  distribu- 
tion of  these  are  matters  of  individual  taste. 
There  is  no  one  of  them  that  does  not  offer  oppor- 
tunities for  interesting  experiments  and  improve- 
ment, but  the  details  of  these  experiments  are 

[201] 


LUTHER  BURBANK 

readily  mastered  by  anyone  who  has  grasped  the 
fundamental  ideas  of  plant  development  through 
hybridization  and  selection.  A  few  words  must  be 
added,  however,  about  the  shrubs  and  vines  that 
break  up  the  long  stretches  and  furnish  an  essen- 
tial border  or  background  of  foliage  on  the  walls 
or  trellises  or  pergolas  about  your  lawn.  No  door- 
yard  is  quite  complete  without  such  a  background. 

Needless  to  say,  Mr.  Burbank  has  not  over- 
looked this  esthetic  requirement.  n  Among  the 
shrubs  and  small  trees  of  more  familiar  type  with 
which  he  has  worked  extensively  in  producing  ma- 
terials for  hedge  or  lawn  decoration  are  the  black 
alder,  the  barberry,  the  flowering  dogwood,  the 
sumac,  the  elder,  the  hazelnut,  the  mulberry,  the 
osage  orange,  the  laurel,  the  rhododendron,  the 
witchhazel,  the  wild  plum,  and  the  abutilon  or 
flowering  maple  from  Chile.  ^ } 

All  these  have  attractive  qualities  of  foliage, 
and  a  good  many  of  them  have  added  attractive- 
ness because  of  their  beautiful  flowers  or  their 
edible  fruits.  Almost  all  of  them  give  oppor- 
tunity for  experiments  in  development  by  cross- 
breeding and  selection,  that  add  to  their  attrac- 
tiveness from  the  present  standpoint.  If  you  have 
none  of  them  on  your  grounds,  it  will  be  well  to 
secure  a  few  for  transplantation  this  autumn,  to 
be  ready  for  hybridizing  experiments  next  season. 

With  the  ornamental  vines,  Mr.  Burbank  has 
worked  no  less  extensively,  and  he  has  developed 
these  in  sufficient  variety  and  profusion  to  meet 
every  need.  The  ivies,  for  example,  have  been 

[202] 


LAWN  AND  DOCKYARD 

given  a  vast  deal  of  attention,  in  particular  the 
members  of  the  genus  Ampelopsis,  of  which  the 
Japanese  ivy  and  the  Virginia  creeper  are  per- 
haps the  best  known.  One  of  his  new  varieties  of 
Virginia  creeper  is  an  extremely  rapid  grower, 
and  has  the  habit  of  holding  its  foliage  until  a 
late  period  in  the  autumn. 

Mr.  Burbank  has  been  unable  to  hybridize  the 
Japanese  ivy  and  the  Virginia  creeper,  but  he  says 
that  he  sees  no  reason  why  the  two  should  not 
be  crossed,  and  he  believes  that  if  the  combination 
could  be  made,  it  would  result  in  the  production 
of  new  vines  of  almost  priceless  value.  The  num- 
ber of  ornamental  vines  is  comparatively  limited, 
and  an  addition  to  the  list  would  be  welcomed. 
Here,  then,  is  a  field  in  which  the  amateur  may 
advantageously  work.  You  may  readily  grow 
both  the  Japanese  ivy  and  the  Virginia  creeper, 
and  the  attempt  to  hybridize  them  would  have 
added  interest  because  of  the  uncertainty  of  the 
result. 

A  vine  with  which  Mr.  Burbank  has  attained 
exceptional  success  is  the  beautiful  clematis.  This 
vine  not  only  rivals  the  ivies  in  its  capacity  to 
clamber  over  walls  and  arbors,  but  it  has  the 
added  merit  of  producing  remarkable  flowers. 
Even  the  native  wild  species  produce  attractive 
blossoms,  and  the  hybrid  species  that  Mr.  Bur- 
bank  has  developed  have  a  variety  of  flowers  of 
extraordinary  interest  and  beauty. 

The  familiar  wild  form  has  single  star-like 
flowers  of  comparatively  small  size.  The  hybrid 

[203] 


LUTHER  BURBANK 

varieties,  produced  by  blending  the  strains  of 
eight  or  ten  species,  show  an  extraordinary  range 
of  variation  both  as  to  form  and  color  of  flower. 
The  petals  of  some  varieties  have  a  singular 
frosted  appearance.  Some  of  them  are  bell- 
shaped,  others  have  petals  that  are  fluted  and 
feathery,  bearing  a  curious  resemblance  to  ostrich 
plumes. 

Unfortunately  some  of  the  new  varieties  of 
clematis  are  somewhat  lacking  in  hardiness. 
There  are  several  wild  species,  however,  that 
grow  in  the  regions  of  northern  Canada  where 
the  mercury  goes  fifty  or  sixty  degrees  below 
zero.  It  is  certain  that  further  hybridizing  ex- 
periments in  which  these  hardy  species  were  util- 
ized would  result  in  giving  new  varieties  that 
would  combine  the  qualities  of  flower  of  Mr.  Bur- 
bank's  beautiful  clematis  with  the  hardiness  of  the 
northern  race. 

Other  ornamental  vines  with  which  Mr.  Bur- 
bank  has  worked  extensively  are  the  bignonia,  the 
wistaria,  and  the  bellflower.  He  points  out  that 
a  good  deal  of  work  remains  to  be  done  by  cross- 
ing the  hardy  bignonias  with  the  tender  ones, 
there  being  excellent  prospect  that  new  varieties 
of  value  will  thus  be  produced.  The  wistarias, 
also,  he  says,  offer  interesting  possibilities.  They 
are  difficult  to  pollenize  because  their  flowers  are 
papilionaceous,  like  those  of  the  peas  and  beans. 
But  anyone  who  has  experimented  with  the  latter 
will  have  no  difficulty  with  the  wistarias.  Mr. 
Bnrbank  suggests  that  some  very  striking  varia- 

[204] 


LAWN  AND  DOCKYARD 

tions  should  be  obtained  in  the  second  generation 
from  a  cross  between  the  American  and  the 
Chinese  species. 

The  Chilean  bellflower  is  another  ornamental 
vine  that  bears  beautiful  flowers.  Mr.  Burbank 
regards  this  as  among  the  most  beautiful  of  all 
blossoms.  He  describes  it  as  a  glorious,  great 
drooping  bell-shaped  rosy  or  white  blossom,  which 
no  lover  of  flowers  could  fail  to  admire.  Unfor- 
tunately the  plants  are  very  difficult  to  raise,  need- 
ing peculiar  soil  and  much  attention.  They  are 
also  sensitive  to  changes  of  temperature,  and  they 
must  be  kept  moist  at  all  times.  Mr.  Burbank  has 
experiments  under  way  in  which  the  attempt  will 
be  made  to  hybridize  this  plant  with  other  forms, 
in  the  hope  of  securing  a  new  ornamental  vine 
that  will  be  adapted  to  our  northern  climate. 

Meantime  the  amateur  will  perhaps  do  well  to 
begin  his  experiments  with  the  hardier  material 
supplied  by  the  ivies,  clematis,  and  wistaria. 
These,  however,  give  ample  opportunity  for  the 
exercise  of  ingenuity,  and  full  promise  of  inter- 
esting developments. 


[205] 


CHAPTER  X 
BURBANK'S  WAY  WITH  TREES 

OF  the  many  extraordinary  things  observed 
when  I  first  visited  Mr.  Burbank,  perhaps 
nothing  impressed  me  more  than  the  ex- 
perience at  Sebastopol,  when  the  plant  developer, 
with  eyes  a-twinkle,  invited  me  to  "  stoop  down 
and  pick  some  chestnuts  from  the  top  of  yonder 
tree." 

The  invitation  was  one  that  could  be  accepted  in 
a  literal  sense ;  for  we  were  standing  in  the  midst 
of  what  might  be  termed  a  chestnut  forest  in  mini- 
ature. About  us  were  "trees"  heavily  laden  with 
chestnut  burs  inclosing  nuts  of  the  very  largest 
size ;  and  the  tops  of  said  trees  were  some  of  them 
only  knee-high,  others  being  as  high  as  the  waist. 
One  had  literally  to  stoop  if  one  wished  to  touch 
the  tops  of  many  of  these  anomalous  nut-bearers. 

Yet  the  burs  with  which  these  miniature  trees 
were  laden  were  obviously  chestnut  burs,  the 
leaves  of  the  trees  were  those  of  the  chestnut, 
and  the  nuts  themselves  were  found,  on  testing, 
to  be  chestnuts  not  only  of  extraordinary  size  but 
of  the  finest  quality. 

To  one  who  is  accustomed  to  gather  chestnuts 
on  occasion  that  have  fallen  from  branches  scores 

[206] 


BURBANK'S  WAY  WITH  TREES 

of  feet  in  the  air,  it  seemed  a  culminating  paradox 
to  find  larger  chestnuts  than  the  mammoth  trees 
of  the  East  ever  produce  growing  on  tiny  bushes. 
White  blackberries  and  thornless  briers,  stoneless 
plums  and  seedless  grapes,  cactus  slabs  without 
spines,  perfumed  callas,  blue  poppies, — I  am  not 
sure  that  any  of  these  seem  quite  so  paradoxical 
as  the  dwarfed  chestnut  tree  with  its  load  of  mam- 
moth nuts. 

It  goes  without  saying  that  the  anomalous 
chestnuts  have  an  interesting  history.  Although 
they  are  still  undergoing  training  in  the  plant 
school  at  Sebastopol,  they  are  nevertheless  among 
the  most  ancient  of  Mr.  Burbank's  remarkable 
plant  productions.  The  experiments  that  led  to 
their  production  were  begun  as  long  ago  as  the 
year  1884.  In  the  autumn  of  that  year  Mr.  Bur- 
bank  received  his  first  shipment  of  plant  products 
from  Japan.  Among  the  varied  things  thus  im- 
ported from  the  Orient,  few  had  more  interesting 
possibilities  than  the  packet  that  was  labeled  in 
a  memorandum:  "Twenty-five  monster  chest- 
nuts." 

Some  years  earlier,  while  Mr.  Burbank  was  still 
a  young  man  in  the  East,  he  had  observed  that 
the  American  chestnut  varies  rather  strikingly, 
some  trees  producing  much  finer  nuts  than  others ; 
and  had  noted  this  variability  as  seeming  to  offer 
opportunities  for  selective  breeding.  Now  it  oc- 
curred to  him  that  the  Japanese  chestnuts  gave 
material  for  hybridizing  experiments  through 
which  the  natural  tendency  to  variation  might 

[207] 


LUTHER  BURBANK 

be  accentuated.  That  remarkable  results  would 
thereby  be  attained  the  plant  developer  had  no 
doubt.  Just  what  these  results  would  be,  it  re- 
mained for  the  sequel  to  determine. 

HOW   THE   PKECOCIOUS   DWARFS   WERE    MADE 

There  were  already  at  hand  at  Santa  Rosa 
specimens  of  the  ordinary  American  chestnut  of 
the  Northeast  and  of  the  somewhat  closely  re- 
lated European  chestnut,  as  well  as  of  the  small 
allied  species  of  our  southeastern  states,  known 
as  the  chinquapin.  Mr.  Burbank  at  once  set  about 
blending  the  strains  of  these  three  species  with 
the  strains  of  the  newcomer  from  the  Orient. 
Each  species  was  crossed  with  all  the  others,  that 
the  results  of  different  combinations  might  be 
tested. 

Of  course  the  hybrid  of  the  first  filial  genera- 
tion blends  the  strains  of  only  two  species.  But 
it  is  equally  obvious  that  if  these  hybrids  are 
themselves  interbred,  the  strains  of  four  species 
may  be  combined  in  the  complex  hybrid  of  the  sec- 
ond filial  generation.  For  example,  the  hybrid 
progeny  of  the  Japanese  chestnut  and  the  chin- 
quapin crossed  with  the  hybrid  progeny  of  the 
European  and  American  chestnuts  will  produce 
offspring  in  which  the  strains  of  the  four  species 
are  evenly  blended.  It  is  not  to  be  expected,  of 
course,  that  this  hybrid  will  combine  the  desirable 
qualities  of  the  parents  in  just  the  right  propor- 
tion. But  some  of  the  desirable  qualities  will  be 

[208] 


BURBANK'S  WAY  WITH  TREES 

shown  by  a  few  at  least  of  the  progeny  having 
this  complex  heritage. 

Suppose,  for  the  sake  of  illustration,  that  one 
of  these  second-generation  hybrids  is  exceedingly 
productive  and  bears  a  nut  of  fine  quality  but 
lacking  in  size.  The  next  step  of  the  experiment, 
then,  would  be  to  hybridize  this  individual  with 
the  Japanese  chestnut,  one  of  its  grandparents, 
which  bears  very  large  nuts. 

The  offspring  of  this  cross  will  probably  have 
some  representatives  that  combine  the  exceptional 
qualities  of  one  of  their  parents  with  the  large 
size  of  the  other. 

A  moment's  reflection  will  make  it  clear  that 
where  four  species  are  in  question  it  is  possible 
to  unite  their  strains  in  an  almost  endless  number 
of  combinations  in  successive  generations.  This 
was  precisely  what  Mr.  Burbank  did  in  the  case 
of  chestnuts  from  three  continents.  He  blended 
their  strains  this  way  and  that,  noting  results, 
and  being  guided  thereby  in  making  new  tests; 
until  presently  he  had  quite  the  most  remarkable 
chestnut  trees  that  had  ever  been  seen,  including, 
among  others,  the  dwarfed  forms  to  which  refer- 
ence has  already  been  made. 

But  how,  it  will  naturally  be  asked,  could  ex- 
periments of  this  intricate  character  be  carried  out 
in  one  man's  lifetime,  when  we  are  dealing  with 
a  tree  that  ordinarily  does  not  begin  to  bear  fruit 
until  it  is  several  years  old? 

The  answer  gives  us  an  insight  into  another 
very  remarkable  feature  of  the  experiment. ( '  It 

[209] 


LUTHER  BURBANK 

appears  that  the  chestnuts  with  which  Mr.  Bur- 
bank  was  experimenting  carried  submerged  in 
their  germ-plasm  the  possibilities  of  very  pre- 
cocious bearing.  Always  on  the  alert  to  observe 
variation  in  this  direction,  Mr.  Burbank  selected 
eagerly  among  the  hybrid  seedlings  even  of  the 
first  generation  for  those  that  showed  a  pro- 
pensity to  rapid  growth  and  early  development. 
0  By  breeding  only  from  these  more  precocious 
plants,  he  had  presently  developed  races  of  hy- 
brid chestnuts  that  would  blossom  and  fruit  in 
their  second  year,  if  their  stalks  were  cut  and 
grafted  on  branches  of  older  trees. 

Continuing  the  experiment,  he  finally  developed 
plants  so  extraordinarily  precocious  as  to  bear 
large,  fully  matured  nuts  on  the  tiny  stalk,  grow- 
ing on  its  own  roots,  in  its  first  season.  Within 
six  months  of  the  time  when  a  chestnut  was 
planted,  the  plant  that  sprang  from  that  seed 
might  bear  its  two  or  three  burs  of  chestnuts,  thus 
rivaling  the  familiar  annual  plants  in  its  precocity 
of  development,  and  seeming  to  bid  defiance  to  the 
hereditary  traditions  of  nut-bearing  trees. 
(!  In  their  succeeding  years  these  precocious 
chestnuts  attain  the  size  of  bushes,  but  they  have 
lost  utterly  the  capacity  to  grow  to  tree-like  dimen- 
sions. In  leaf  and  fruit  they  are  unmistakably 
chestnuts,  but  in  manner  of  growth  they  have  de- 
parted absolutely  from  the  recognized  traditions 
of  their  family. ' ' 

It  should  be  explained,  perhaps,  that  the  an- 
cestors of  these  precocious  dwarfs  were  selected 

[210] 


BURBANK'S  WAY  WITH  TREES 

from  among  thousands  of  hybrid  seedlings. 
Among  the  thousands,  there  were  of  course  repre- 
sentatives of  numberless  different  combinations 
of  the  ancestral  traits  of  the  four  parent  species. 
It  would  have  been  possible  to  develop  gigantic 
races  as  well  as  dwarfed  ones.  Some  of  the  speci- 
mens first  developed  were  of  large  size  and  enor- 
mously prolific.  But  to  Mr.  Burbank  it  seemed 
that  the  most  desirable  type  of  chestnut  Tor  the 
purposes  of  the  horticulturist  would  be  one  that 
produced  an  abundant  crop  of  exceedingly  large 
nuts  on  a  tree  that  attained  only  shrub-like  pro- 
portions. So  his  selections  were  made  with  this 
idea  in  mind,  and  the  dwarfed  chestnuts  of  Sebas- 
topol  are  the  tangible  exemplification  of  that  ideal. 

In  conducting  his  experiments,  of  course  Mr. 
Burbank,  here  as  always,  had  in  mind  a  great 
variety  of  desirable  qualities.  One  of  his  novelties 
is  a  line  of  hybrid  chestnuts  in  which  the  burs 
are  being  deprived  of  their  spines  through  selec- 
tive breeding. 

It  has  been  pointed  out  that  he  seeks  always 
to  develop  plants  that  show  great  resistance  to 
disease.  The  hybrid  chestnuts  are  no  exception 
to  the  rule.  There  is  reason  to  believe  that  they 
are  immune  to  the  attacks  of  the  fungous  pest  that 
has  destroyed  the  native  chestnuts  everywhere  in 
the  neighborhood  of  New  York,  and  which  is  ex- 
tending its  ravages  in  all  directions  year  by  year, 
with  full  prospect  that  ultimately  it  will  leave  no 
tree  of  this  species  standing  between  Maine  and 
the  Carolinas. 

[211] 


LUTHER  BURBANK 

The  destruction  of  our  native  chestnuts  has  been 
justly  regarded  as  a  calamity.  It  is  a  consolation 
to  know  that  the  hybrid  chestnut  will  probably  be 
available  to  restock  the  devastated  regions  with 
a  tree  that  will  more  than  compensate  for  the  loss 
of  the  native  chestnut  as  a  producer  of  nuts. 

Doubtless  it  will  be  possible  also  to  produce 
hybrid  strains  that  will  combine  immunity  to  the 
pest  with  capacity  for  lumber  production,  at  least 
equal  to  that  of  our  native  tree,  and  perhaps 
vastly  superior. 

THE  PEODUCTION  OF  GIANTS 

The  warrant  for  the  latter  supposition  is  found 
in  a  line  of  experiments  conducted  by  Mr.  Burbank 
with  another  tribe  of  nut-bearers;  namely,  the 
walnuts.  His  success  in  producing  extraordinary 
giants  of  this  tribe  was  no  less  striking,  and  in 
some  respects  even  more  important,  than  his  feat 
of  producing  the  dwarfed  chestnuts.  The  story 
of  this  accomplishment  must  be  told  in  detail,  as 
it  furnishes  an  insight  into  what  ultimately  may 
prove  the  most  important,  from  an  economic 
standpoint,  of  all  Mr.  Burbank 's  discoveries. 

The  initial  experiments  in  this  case  also  were 
made  many  years  ago,  so  that  successive  genera- 
tions of  the  remarkable  trees  in  question  are  in 
evidence.  These  trees  are  of  two  distinct  tribes. 
One  of  them  originated  through  hybridizing  the 
indigenous  California  black  walnut  with  the  Per- 
sian walnut  (commonly  called  English  walnut), 

[212] 


BURBANK'S  WAY  WITH  TREES 

the  other  through  hybridizing  the  California  black 
walnut  with  the  black  walnut  of  the  eastern  United 
States,  which  is  a  distinct  species. 

The  cross  between  the  two  species  of  black  wal- 
nut resulted  in  the  production  of  a  tree  that  grew 
with  extraordinary  rapidity,  and  that  ultimately 
proved  an  enormously  prolific  bearer  of  nuts. 
This  hybrid  tree  was  given  the  name  of  the  Royal 
walnut.  It  differed  somewhat  in  appearance  from 
either  of  its  parents,  but  its  most  striking  pecul- 
iarity was  its  amazing  capacity  for  growth  and  its 
no  less  amazing  fecundity.  The  individual  nuts 
that  it  bore  were  considerably  larger  than  those 
of  either  parent,  and  the  crop  was  multiplied 
many  fold. 

Long  before  the  Royal  hybrid  had  come  to  the 
age  of  bearing,  however,  Mr.  Burbank  had  made 
the  successful  experiment  of  crossing  the  Cali- 
fornia black  walnut  with  the  Persian  walnut. 
This  was  a  far  more  remarkable  cross,  because  the 
species  are  much  less  closely  related,  one  of  them 
being  indigenous  to  the  eastern  hemisphere,  the 
other  a  native  of  California. 

The  hybrid  offspring  of  these  widely  different 
trees  showed  such  striking  peculiarities  that  it 
was  named  the  Paradox  walnut. 

Like  the  Royal  hybrid  just  referred  to,  the 
Paradox  showed  an  extraordinary  capacity  for 
growth.  It  sprang  up  and  increased  month  by 
month  and  year  by  year  at  a  rate  altogether  un- 
suggestive  of  the  characteristics  of  either  parent. 
When  nine  years  old  trees  of  this  mixed  heritage 

[213] 


LUTHER  BURBANK 

towered  far  above  the  parent  Persian  walnut,  still 
standing  just  across  the  way,  and  then  in  its 
twenty-ninth  year.  The  foliage  of  the  Paradox 
hybrid  resembles  in  form  of  leaf  that  of  the  Per- 
sian walnut  on  a  magnified  scale ;  but  the  individ- 
ual leaves  are  much  more  numerous  on  the  leaf 
stalk,  showing  the  influence  of  the  California 
parent.  The  bark  of  the  tree  is  light  in  color,  not 
dissimilar  to  that  of  its  European  progenitor. 

For  a  number  of  years  the  Paradox  was  sup- 
posed to  be  altogether  sterile,  and  although  in  sub- 
sequent years  it  produced  a  few  nuts  which  proved 
to  be  viable,  it  never  bore  more  than  a  very  small 
fraction  of  the  crop  that  was  habitual  with  its 
Royal  cousin.  Seemingly  the  hereditary  gap  be- 
tween the  parents  was  so  wide  as  to  carry  it  al- 
most to  the  limits  of  affinity ;  whereas  the  relation- 
ship between  the  two  species  of  black  walnut  was 
precisely  such  as  to  insure  enhanced  fecundity. 

Yet  in  point  of  individual  vigor  the  Paradox 
competes  on  an  even  footing  with  the  other  tree. 
Indeed,  these  trees  vie  with  each  other,  and  defy 
the  competition  of  all  other  trees  in  their  rapidity 
of  growth,  and  in  the  gigantic  stature  that  they 
attain  at  a  relatively  early  age.  There  are  sev- 
eral individual  specimens  of  these  interesting  hy- 
brids at  Santa  Rosa  and  Sebastopol  that  are  now 
more  than  twenty  years  old.  To  anyone  familiar 
with  the  habit  of  growth  of  uncrossed  walnuts, 
who  observed  them  without  knowing  their  origin, 
it  would  appear  that  they  must  be  at  least  three- 
quarters  of  a  century  old. 

[214] 


BURBANK'S  WAY  WITH  TREES 

Notwithstanding  the  extraordinarily  rapid 
growth  of  these  trees,  however,  it  was  found  that 
the  wood  they  produce  is  of  the  hardest  texture, 
capable  of  taking  on  an  excellent  cabinet  finish. 
Most  trees  that  grow  with  relative  rapidity  pro- 
duce soft  wood,  but  these  hybrid  walnuts  are 
notable  exceptions  to  the  rule.  The  timber  they 
produce  is  in  no  wise  inferior  to  that  of  the  parent 
black  walnut;  and  this  wood,  as  is  well  known, 
was  so  famous  for  its  quality  that  the  trees  pro- 
ducing it  were  almost  exterminated  in  the  United 
States. 

Here,  then,  are  revealed  new  possibilities  of 
the  production,  through  hybridization,  of  timber 
trees  of  unrivaled  capacity  for  growth. 

The  possibility  of  restocking  deforested  regions 
with  trees  of  such  rapid  growth  is  very  alluring. 
The  most  disheartening  feature  of  the  entire  prob- 
lem of  reforestation  has  been  the  fact  that  trees 
that  make  good  timber  are  so  universally  ob- 
served to  be  of  slow  growth.  An  oak  fifty  years 
old  is  a  tree  of  relatively  insignificant  size;  an- 
other half-century  is  required  to  make  it  a  tree 
of  commendable  proportions.  Even  the  relatively 
quick-growing  chestnut  and  elm  are  three- 
quarters  of  a  century  old  before  they  assume  pro- 
portions that  could  be  called  imposing. 

But  hybridization  so  stimulates  the  vigor  of  the 
walnut  that  it  sometimes  grows  ten  times  as  fast 
as  either  of  its  parents.  Some  of  Mr.  Burbank's 
trees  increase  by  a  full  inch  in  diameter  in  a  single 
year.  At  ten  years  from  seed,  these  hybrids  are 

[215] 


LUTHER  BURBANK 

beginning  to  assume  proportions  that  make  them 
have  value  in  the  eyes  of  the  lumberman.  At 
twenty  years  they  are  handsomely  proportioned 
trees  of  notable  dimensions. 

The  contrast  between  a  Paradox  or  a  Royal  wal- 
nut and  a  black  walnut  or  a  Persian  walnut  of 
the  same  age,  at  any  stage  of  growth,  is  startling. 

If  we  attempt  to  explain  these  anomalies  of 
growth,  we  must  assume  that  the  remote  an- 
cestors of  the  walnuts — away  back,  let  us  say,  in 
the  preglacial  days — were  trees  of  gigantic  size. 
Their  descendants  of  our  day  are  a  relatively  de- 
generate lot,  made  so  by  the  modified  climate  to 
which  they  have  been  obliged  to  adapt  themselves. 
But  the  mingling  of  germ-plasms  of  the  different 
species  makes  it  possible,  in  some  way  that  we  as 
yet  do  not  very  clearly  understand,  for  the  heredi- 
tary factors  of  giganticism,  long  submerged,  to 
make  their  influence  felt. 

A  somewhat  similar  stimulus  to  vigor  of  growth 
is  a  not  unusual  attribute  of  hybrids.  We  have 
seen  that  many  of  the  large  fruits  and  flowers  and 
vegetables  that  Mr.  Burbank  has  produced  are 
thus  to  be  explained.  But  the  case  of  the  walnuts 
is  so  extreme  that  these  trees  stand  in  a  class  by 
themselves.  It  is  doubly  significant  because  these 
are  the  first  experiments  in  hybridizing  forest 
trees  that  produced  notable  results ;  and  because, 
as  I  said,  the  ultimate  economic  importance  of  this 
discovery  can  scarcely  be  overestimated. 

There  is  apparently  no  reason  why  the  same 
principle  of  hybridization  should  not  be  extended 

[216] 


A  NEW  BURBANK  ROSE 

Mr.  Burbank  has  experimented  very  extensively  with  roses,  producing  many 
new  varieties,  one  of  which  took  the  gold  medal  at  the  St.  Louis  exposition. 
The  specimen  here  shown  was  selected  almost  at  random  from  among  hun- 
dreds that  were  equally  attractive. 


BURBANK'S  WAY  WITH  TREES 

to  other  forest  trees,  giving  us  oaks  and  maples 
and  hickories  of  rapid  growth,  to  repopulate  the 
hillsides  and  valleys  of  our  eastern  states  made 
barren  through  the  cupidity  and  lack  of  foresight 
of  our  ancestors. 


SECOND-GENERATION   HYBEIDS 

In  point  of  fact,  nature  herself  occasionally 
points  the  way  by  making  a  demonstration  of  the 
value  of  hybridization  in  the  case  of  forest  trees, 
quite  along  Burbankian  lines,  as  we  shall  see  pres- 
ently. But  for  the  moment  I  wish  to  trace  a  little 
farther  the  history  of  the  hybrid  walnuts,  for 
these  show  interesting  developments  in  the  second 
generation  that  are  full  of  significance. 

Second-generation  hybrids  of  the  Royal  walnuts 
were  readily  enough  secured,  since  this  tree,  as  we 
have  seen,  proved  enormously  prolific.  The  value 
of  the  new  tree,  particularly  to  furnish  roots  on 
which  to  graft  scions  of  the  Persian  walnut,  was 
early  recognized,  and  Mr.  Burbank  sold  in  one 
season  more  than  a  thousand  dollars '  worth,  from 
a  single  hybrid  tree  to  be  used  for  seed  purposes. 
The  Paradox  walnut,  on  the  other  hand,  produced 
so  very  scant  a  harvest  that  it  could  be  multiplied 
but  slowly.  Such  nuts  as  they  did  produce,  how- 
ever, proved  to  be  viable. 

But  the  seedlings  that  grew  from  nuts  of  both 
Eoyal  and  Paradox  walnuts  proved  to  be  a  most 
variable  company.  Some  of  them  showed  capacity 
for  growth  fully  equaling  that  of  their  hybrid  par- 

[217] 


LUTHER  BURBANK 

ents;  but  others  were  extraordinarily  dwarfed, 
growing  far  less  rapidly  than  ordinary  walnuts. 
Plants  side  by  side,  grown  from  nuts  picked  from 
the  same  stem,  might  differ  so  radically  that  they 
would  seem  to  belong  to  totally  unrelated  species. 
One  seedling  might  grow  ten  inches  in  height, 
while  the  one  beside  it  had  grown  but  half  an  inch. 
And  this  disparity,  as  was  shown  in  due  course, 
would  be  retained  throughout  the  life  of  the  trees. 
The  seedling  that  sprang  up  rapidly  and  showed 
vigor  from  the  start  had  potentialities  of  a  giant 
tree;  while  the  weakling  beside  it  was  prenatally 
doomed  to  remain  forever  a  dwarf. 

The  nuts  produced  by  the  Paradox  walnut  were 
so  few  in  number  that  Mr.  Burbank  was  enabled 
to  plant  them  all  and  to  note  carefully  the  char- 
acteristics of  the  seedlings  that  grew  from  them. 
He  observed  that  about  one-third  of  these  seed- 
lings revealed  the  characteristics  of  the  Persian 
walnut,  one  of  their  grandparents;  that  another 
third  tended  to  revert  in  the  opposite  direction 
toward  their  black- walnut  grandparent ;  and  that 
the  remaining  third  were  intermediate  in  char- 
acter, reproducing  more  or  less  closely  the  char- 
acteristics of  their  hybrid  parent. 

It  is  interesting  to  note  that  Mr.  Burbank  re- 
corded this  observation  in  his  printed  catalogue 
of  1898,  in  offering  the  nuts  of  the  Paradox  walnut 
for  sale. 

iV  7  This  observation  regarding  the  hybrids  of  the 
second  filial  generation  is  substantially  in  accord 
with  what  has  since  become  famous  as  the  Men- 

[218] 


BURBANK'S  WAY  WITH  TREES 

delian  formula,  which  at  that  time  was  quite  un- 
known to  the  scientific  world.  The  formula  had 
indeed  been  discovered  by  Mendel  as  long  ago 
as  1863,  but  the  paper  in  which  he  announced  his 
discovery  remained  quite  unknown  until  it  was 
brought  to  light  in  1900  by  Professor  Hugo  De 
Vries  and  two  other  European  botanists. 

Mr.  Burbank  had  observed  the  tendency  to 
segregation  and  redistribution  of  characters  in 
second-generation  hybrids,  which  is  the  essential 
feature  of  Mendelian  heredity  not  alone  in  the 
case  of  the  walnuts,  but  in  hundreds  of  other  hy- 
brids, and  for  many  years  his  experiments  have 
all  been  carried  out  with  an  eye  to  taking  advan- 
tage of  this  observed  natural  phenomenon.  But 
for  many  years  after  the  death  of  Mendel  (which 
occurred  in  1884)  Mr.  Burbank  was  probably  the 
only  prominent  plant  experimenter  in  the  world 
who  clearly  grasped  the  import  of  the  law  of  in- 
heritance, according  to  which  hybrids  of  the  first 
generation  are  relatively  uniform  and  hybrids  of 
the  second  generation  enormously  variable. 

Mr.  Burbank  was  too  busy  making  practicable  (pr<L<J 
application  of  this  discovery  (which  of  course  was 
made  by  him  quite  independently)  to  give  thought 
to  the  publication  of  his  observations.  But  such 
incidental  publication  as  that  just  cited  serves  to 
fix  his  claim  to  independent  discovery;  and  the 
long  list  of  remarkable  plant  developments  in 
many  fields  that  were  carried  out  at  Santa  Eosa 
and  Sebastopol  prior  to  1900  by  application  of 
what  is  essentially  the  Mendelian  principle  very 

[219] 


LUTHER  BURBANK 

tangibly  demonstrates  the  clearness  with  which 
the  "  wizard  of  Santa  Kosa"  had  grasped  this 
fundamental  principle  of  inheritance. 

I  mention  the  matter  here  because  it  has  some- 
times been  assumed  that  Mr.  Burbank  is  a  mere 
" practical"  plant  experimenter  who  has  no  knowl- 
edge of  theoretical  biology.  Practical  he  surely 
is,  and  at  all  times  he  has  considered  that  results 
are  more  important  than  methods;  yet  he  never 
could  have  obtained  the  results  that  have  made 
him  famous  had  he  not  from  the  outset  had  the 
clearest  comprehension  of  the  subtlest  principles 
of  heredity,  and  the  most  sharply  defined  notions 
as  to  the  methods  through  which  these  principles 
could  be  made  available. 

HYBKID   ALMONDS 

Perhaps  it  is  not  too  much  to  say  that  the  prin- 
ciple that  hybridization  of  different  species  may 
produce  new  races  sometimes  entitled  to  specific 
rank  was  an  original  discovery  made  by  Mr.  Bur- 
bank  and  demonstrated  by  him  as  it  has  been  dem- 
onstrated by  no  one  else.  Even  to  this  day  a  good 
many  biologists  refuse  to  recognize  this  principle 
as  an  important  factor  in  the  evolution  of  species. 
Yet  it  is  hard  to  doubt  its  cogency  when  one 
has  had  opportunity  to  examine  the  extraordinary 
new  races  that  Mr.  Burbank  has  thus  produced. 

We  have  just  seen  striking  illustrations  of  this 
in  the  case  of  several  species  of  nut-bearing  trees. 
Other  illustrations  no  less  striking,  though  quite 

[220] 


BURBANK'S  WAY  WITH  TREES 

different  in  their  specific  application,  are  fur- 
nished by  a  long  series  of  experiments  made  by 
Mr.  Burbank  in  which  the  almond  tree  was  one 
of  the  parents  utilized.  Some  of  these  experi- 
ments consisted  of  crossing  the  almond  with  the 
Japanese  plum;  in  other  cases  the  strains  of  the 
almond  were  combined  with  those  of  the  nectarine 
and  the  peach.  In  describing  the  fruit  of  this 
hybrid,  Mr.  Burbank  says  that  it  may  be  char- 
acterized as  fairly  intermediate  between  the  fruits 
of  the  parent,  yet  on  the  whole  the  flesh  of  the 
peach  and  the  stone  of  the  almond  respectively 
tended  to  be  prepotent  or  dominant.  This  is  per- 
haps what  would  be  expected  when  we  recall  that 
the  flesh  is  the  specialized  modern  development 
in  the  case  of  the  peach,  and  that  the  seed  is 
similarly  specialized  and  developed  in  the  case  of 
the  almond.  We  have  seen  that  there  is  reason 
to  believe  that  prepotency  or  dominance  is  con- 
ditioned on  newness  of  development,  and  the  case 
of  the  peach-almond  hybrid  gives  a  measure  of 
support  to  this  theory. 

In  the  second  generation  these  hybrids  of  the 
peach  and  almond  show  an  astonishing  variation 
in  size,  rapidity  of  growth,  and  almost  every  qual- 
ity of  flower  and  fruit.  As  to  the  fruit,  some 
specimens  tend  to  reproduce  the  almond  quality, 
others  the  peach  quality;  yet  others  combine  the 
quality  of  the  two  fruits.  The  best  of  these 
second-generation  hybrids  bear  fruits  that  are 
obviously  peaches,  even  peaches  of  a  fair  quality, 
yet  have  at  their  center  what  is  at  once  recog- 

[221] 


LUTHER  BURBANK 

nized  as  an  almond  nut  with  characteristic  shell 
and  seed. 

In  a  word,  these  are  almonds  grown  inside  the 
peach, — a  combination  of  obvious  interest. 

As  yet  this  anomalous  fruit  has  not  attained 
commercial  importance,  because  the  varieties  thus 
far  produced  are  not  peaches  of  the  highest  grade ; 
neither  do  they  bear  almond  nuts  of  the  first 
quality. 

It  would  be  necessary  to  continue  the  experi- 
ment through  successive  generations,  crossing  the 
hybrids  successively  with  peaches  and  almonds  of 
the  finest  quality,  in  order  to  produce  a  peach- 
almond  that  could  compete  advantageously  in  the 
market  with  the  varieties  of  peaches  and  of  al- 
monds already  under  cultivation.  It  is  probable 
that  ultimately  this  experiment  will  be  carried  out. 
It  lies  within  the  reach  of  any  amateur  who  lives 
in  a  region  where  peaches  and  almonds  will  grow. 

As  to  the  almond  itself,  there  is  opportunity 
for  improvement  in  the  way  of  producing  varie- 
ties that  will  bear  large  crops  with  regularity. 
The  shell  of  the  best  cultivated  varieties  is  per- 
haps as  soft  as  is  desirable,  as  it  is  liable  to  injury 
in  shipping  if  it  becomes  too  friable.  But  it  might 
be  possible  to  develop  a  variety  that  would  have 
white  shells,  thus  obviating  the  necessity  for 
bleaching  with  the  fumes  of  sulphur,  which  con- 
stitutes a  somewhat  expensive  feature  of  the  pres- 
ent almond  industry. 

Incidentally,  it  is  worth  while  to  note  that  the 
almond  industry  has  attained  a  good  degree  of 

[222] 


BURBANK'S  WAY  WITH  TREES 

importance  in  recent  years.  As  to  the  actual  num- 
ber of  nut-bearing  trees  under  cultivation,  the 
almond  heads  the  list,  the  trees  in  bearing  in  1910 
numbering  1,187,962,  in  addition  to  which  there 
were  almost  400,000  young  trees  not  yet  in  bear- 
ing. The  total  marketable  production  of  almonds 
in  1909  had  a  value  of  more  than  $700,000. 

OTHEE   HYBKIDIZING  POSSIBILITIES 

When  the  economic  value  of  nuts  is  under  con- 
sideration, however,  the  palm  must  be  yielded  to 
the  Persian  walnut,  which  produced  in  1909  a  crop 
valued  at  $2,297,000.  The  number  of  walnut  trees 
in  bearing  was  less  than  the  number  of  almond 
trees,  but  the  value  of  the  crop  borne  on  an  indi- 
vidual tree  is  much  larger. 

It  should  be  noted  that  all  but  about  sixty  thou- 
sand of  the  Persian  walnut  trees  in  bearing  in 
1910  in  the  United  States  were  in  California.  But 
the  value  of  walnuts  as  a  market  crop  has  re- 
cently come  to  be  appreciated  elsewhere,  and 
orchards  of  young  trees  are  rapidly  being  intro- 
duced in  other  states,  including,  notably,  Oregon 
and  Mississippi. 

Unfortunately,  the  Persian  walnut  is  not  a 
hardy  tree.  Yet  it  might  be  cultivated  in  many 
regions  where  it  has  hitherto  been  altogether  neg- 
lected ;  and  the  results  obtained  in  California  sug- 
gest that  it  is  well  worth  the  attention  of  horti- 
culturists throughout  the  southern  and  central 
regions  of  the  United  States.  Moreover,  there  is 

[223] 


LUTHER  BURBANK 

a  related  Japanese  species  of  walnut  which  is  an 
exceedingly  prolific  bearer,  and  which  is  as  hardy 
as  our  native  black  walnut. 

Mr.  Burbank  has  experimented  in  hybridizing 
this  tree  with  the  American  walnuts.  The  results 
were  interesting,  in  that  the  hybrids  proved  ex- 
ceedingly variable,  but  they  were  not  commer- 
cially important.  It  is  certainly  worth  while,  how- 
ever, to  extend  these  experiments,  and  it  is  not 
unlikely  that  the  Japanese  walnut  may  prove  a 
valuable  acquisition  if  its  strains  are  blended  in 
just  the  right  way  with  those  of  the  Persian 
walnut. 

Until  recently  very  few  people  in  the  eastern 
United  States  have  thought  of  nuts  of  any  kind 
as  a  crop  for  cultivation.  Now,  however,  it  is 
coming  to  be  understood  that  various  nut-bearers 
are  proper  candidates  for  orchard  treatment,  and 
capable  of  holding  their  own,  or  more  than  their 
own,  as  market  crops,  in  competition  with  the  best 
orchard  fruits.  This  is  notably  the  case  with  the 
walnut  and  almond  and  with  the  pecan  nut,  which 
is  a  relative  of  the  hickories  indigenous  to  the 
Gulf  states. 

The  pecan  flourishes  as  far  north  as  St.  Louis 
and  the  Mississippi  Valley,  in  all  the  Gulf  states, 
and  along  the  South  Atlantic  seaboard. 

The  pecan  nuts  found  in  the  market  are  chiefly 
the  product  of  a  few  varieties  that  were  found  as 
"sports"  in  one  region  or  another  of  the  South, 
and  propagated  by  grafting.  They  do  not  repre- 
sent the  art  of  the  plant  developer,  but  they  iUus- 

[224] 


BURBANK'S  WAY  WITH  TREES 

trate  possibilities  that  are  open  to  the  experi- 
menter. Mr.  Burbank  reports  that  he  has  seen 
nuts  that  he  regards  as  undoubtedly  hybrids  be- 
tween the  pecan  and  the  hickory.  He  suggests 
that  a  new  nut  of  hardy  quality  might  probably 
be  produced  by  hybridizing  the  pecan  with  the 
shagbark  hickory,  and  carrying  the  experiment 
forward  along  the  usual  lines  of  selection.  The 
chief  difficulty  involved  is  that  the  trees  are  of 
slow  growth,  coming  to  maturity  only  after  a  good 
many  years.  Comparatively  few  persons  have  the 
patience  to  work  under  such  conditions.  Yet  there 
is  little  question  that  such  experiments  will  be 
undertaken  in  the  near  future,  and  important  re- 
sults may  be  expected  in  years  to  come. 

It  is  desirable  also  to  attempt  to  hybridize  the 
pecan  with  the  butternut  and  walnut  and  with  the 
English  walnut.  Mr.  Burbank  suggests  that  if 
such  hybridization  could  be  effected,  it  may  be 
expected  that  trees  of  rapid  growth,  similar  to  his 
hybrid  walnuts,  will  be  produced. 

Not  unlikely,  he  says,  some  varieties  that  tend 
to  produce  nuts  at  a  very  early  age,  like  the  hy- 
brid chestnuts,  may  also  appear  as  the  result  of 
such  hybridization. 

And  in  any  event,  it  may  confidently  be  expected 
that  new  varieties  will  give  opportunity  for  wide 
selection,  and  for  relatively  rapid  improvement  in 
the  quality  of  the  nuts  themselves.  There  is  every 
reason  to  believe  that  the  wild  pecan  will  respond 
to  the  efforts  of  the  plant  developer,  and  that  its 
descendants  a  few  generations  removed  will  take 

[225] 


LUTHER  BURBANK 

on  qualities  that  the  most  sanguine  experimenter 
of  to-day  would  scarcely  dare  to  predict. 

As  to  the  technique  of  hybridizing  the  various 
nut-bearers,  there  is  no  difficulty  whatever. 
Chestnuts,  walnuts,  hickories,  and  pecans  all  be- 
long to  a  tribe  of  trees  characterized  by  bearing 
the  staminate  and  pistillate  flowers  in  separate 
clusters.  To  effect  cross-fertilization,  nothing 
more  is  necessary  than  to  bring  a  bunch  of  stam- 
inate flowers,  when  the  pollen  is  ripe,  and  brush 
them  freely  against  a  bunch  of  pistillate  flowers. 

To  avoid  contamination  with  other  pollen,  it 
will  be  advisable  to  tie  a  paper  bag  about  the 
bunch  of  pistillate  flowers,  leaving  it  there  a  few 
days  until  the  stigmas  have  passed  the  receptive 
stage. 

DEVELOPMENT   THKOUGH   SELECTION 

You  need  not  wait  for  the  coming  of  another 
season,  however,  in  order  to  begin  work  with  the 
nut-bearers. 

If  you  will  stroll  into  the  woods  in  your  neigh- 
borhood this  autumn  and  carefully  examine  the 
nuts  fallen  from  different  hickory  trees,  you  will 
quickly  discover  that  these  vary  greatly.  Some 
trees  bear  uniformly  large,  thin-shelled  nuts; 
others  just  as  regularly  bear  small,  thick-shelled 
ones.  Here,  then,  is  opportunity  for  immediately 
beginning  experiments  in  selective  breeding. 

You  must  be  forewarned,  however,  that  the  nuts 
taken  from  any  individual  tree  have  probably  a 

[226] 


BURBANK'S  WAY  WITH  TREES 

wide  range  of  variation  as  to  their  hereditary 
factors ;  so  the  seedlings  grown  from  them  will  be 
by  no  means  uniform.  Some  will  probably  grow 
much  more  rapidly  than  others,  and  when  in  due 
course  they  come  to  maturity,  they  will  vary 
greatly  as  to  the  quality  of  their  nuts. 

But  fortunately  the  seedlings  may  be  fairly  de- 
pended upon  to  show  their  qualities  very  soon 
after  their  cotyledons  break  the  soil.  The  young 
plants  that  are  of  vigorous  growth,  with  relatively 
thick  stems  and  large  fat  buds,  may  safely  be 
preserved  as  having  future  possibilities  greatly 
exceeding  those  of  their  less  thrifty  fellows.  Mr. 
Burbank  assures  us  that  it  is  not  necessary  to 
raise  the  entire  lot  of  seedlings  and  await  their 
time  of  maturing.  You  may  safely  follow  his  ex- 
ample in  selecting  the  ones  that  grow  rapidly 
during  the  first  few  weeks  or  months,  weeding  out 
the  others. 

But  whereas  you  must  expect  a  relatively  wide 
range  of  variation,  it  of  course  is  also  true  that 
on  the  average  the  seedlings  grown  from  nuts  of 
a  tree  that  is  a  good  bearer  will  be  superior  to 
those  grown  from  the  product  of  an  inferior  tree. 
So,  as  a  matter  of  course,  you  will  select  for  seed 
purposes  only  the  very  best  nuts.  In  this  connec- 
tion, however,  you  must  recall  what  has  been  said 
in  the  earlier  articles  about  judging  a  plant  by 
its  total  product  rather  than  by  the  individual 
specimens. 

A  small  individual  nut  from  a  tree  that  gen- 
erally bears  large  nuts  would  have  greater  prom- 

[227] 


LUTHER  BURBANK 

ise  than  a  large  individual  nut  from  a  tree  that 
in  general  bore  small  nuts. 


A  "PAPER-SHELLED"  WALNUT 


As  to  the  possibility  of  rapidly  developing  a 
new  variety  of  nut  through  selection  from  the 
product  of  a  single  tree  of  unusual  quality,  Mr. 
Burbank 's  experience  in  the  production  of  the 
Santa  Eosa  paper-shelled  walnut  is  illuminative. 

The  tree  from  which  this  valuable  variety  was 
developed  was  a  Persian  walnut  of  unknown  ante- 
cedents, that  grew  on  a  San  Francisco  street.  Mr. 
Burbank  noted  that  this  tree  bore  many  nuts  that 
had  exceedingly  thin  shells,  and  even  some  nuts 
that  had  shells  that  did  not  altogether  cover  the 
kernel  of  the  nut, — suggesting  in  this  regard  the 
partially  stoneless  plum  with  which  his  experi- 
ments in  the  development  of  a  race  of  stoneless 
plums  had  been  undertaken. 

Growing  a  large  number  of  seedlings  from  nuts 
of  this  unusual  tree,  and  selecting  among  them  for 
different  qualities,  Mr.  Burbank  had  presently  a 
colony  of  English  walnuts,  some  of  which  pro- 
duced nuts  so  devoid  of  shell  covering  that  the 
birds  discovered  their  lack  of  armament  and  de- 
stroyed the  kernels  by  pecking  at  them.  The  en- 
tire lack  of  shell  proving  thus  a  detriment,  it  was 
necessary  to  conduct  the  further  experiments  in 
selective  breeding  in  the  opposite  direction,  thick- 
ening the  shell  rather  than  eliminating  it.  But 
material  for  these  experiments  was  at  hand,  and 

[228] 


BURBANK'S  WAY  WITH  TREES 

by  careful  selection  Mr.  Burbank  soon  developed 
a  variety  of  walnut  that  had  a  shell  of  just  the 
requisite  thickness,  to  ward  off  the  encroachments 
of  the  birds,  yet  so  thin  that  it  could  be  crushed 
in  the  fingers.  The  tree  that  produced  nuts  with 
this  ideal  quality  of  shell  was  an  abundant  bearer, 
and  the  nuts  themselves  were  of  good  size,  and 
their  meat  was  white  and  of  delicious  quality. 
The  nut  was  introduced  under  the  name  of  the 
Santa  Rosa  Soft-shell  or  Santa  Eosa  Paper-shell. 

Naturally  this  new  variety  soon  became  popu- 
lar. But  Mr.  Burbank  has  been  obliged  to  warn 
the  public  that  they  must  be  on  their  guard  against 
the  purchase  of  seedlings  alleged  to  be  of  the 
Santa  Rosa  paper-shell  variety.  In  point  of  fact, 
this  variety,  like  other  specialized  tribes  of  the 
walnut,  does  not  breed  true  from  seed.  It  must 
be  propagated  by  grafting;  being  precisely  com- 
parable in  this  regard  to  all  of  our  best  varieties 
of  orchard  fruits.  Of  course  trees  bearing  nuts 
of  excellent  quality  may  on  occasion  be  grown 
from  these  nuts,  and  exceptionally  one  of  these 
trees  may  duplicate  very  closely  the  qualities  of 
the  parent  tree.  But  other  trees,  grown  perhaps 
from  nuts  borne  in  the  same  cluster,  may  show  a 
wide  variation,  to  the  great  disappointment  of  the 
misguided  orchardist  who  expected  them  to  show 
the  qualities  of  their  parent. 

Fortunately,  the  grafting  of  the  walnut  repre- 
sents no  great  difficulties  for  anyone  who  has 
facility  in  grafting  orchard  fruits.  In  cleft  graft- 
ing it  may  be  desirable  to  cut  out  a  notch  instead 

[229] 


LUTHER  BURBANK 

of  splitting  the  stock.  It  is  well  to  wax  the  parts 
thoroughly,  and  it  may  be  desirable  to  give  full 
protection  from  the  drying  effects  of  wind  and 
sun  by  placing  a  paper  sack  over  the  scion  while 
it  is  establishing  its  cellular  bearings. 

It  has  been  found  advantageous  by  many  Cali- 
fornia orchardists  to  use  the  Burbank  Royal  wal- 
nut— which,  as  we  have  seen,  is  a  hybrid  between 
the  eastern  and  western  black  walnuts — as  a  stock 
on  which  to  graft  scions  of  the  Persian  walnut. 
The  Eoyal  walnut  has  extraordinary  capacity  for 
growth,  as  above  explained,  and  its  root  imparts 
something  of  its  vigor  to  the  scions  engrafted  on 
its  stem. 

Orchards  thus  established  come  early  to  bear- 
ing, and  prove  far  more  productive,  as  a  rule, 
than  those  grown  on  the  native  roots  of  the 
Persian  walnut. 

As  to  the  matter  of  early  bearing,  which  is 
obviously  of  great  importance  in  the  case  of  com- 
mercial crop,  Mr.  Burbank  has  made  experiments 
with  the  walnuts  that  are  almost  as  interesting 
as  his  experiments  with  precocious  chestnuts.  He 
has  not  been  able  to  make  the  walnut  bear  in  its 
first  season  from  seed,  to  be  sure,  but  he  has  pro- 
duced varieties  that  bear  at  the  age  of  eighteen 
months.  In  general  the  varieties  of  walnuts  that 
he  has  perfected  tend  to  bear  at  an  early  age,  and 
his  experiments  show  that  it  is  possible  to  lessen 
by  several  years  the  time  of  waiting  for  the  seed- 
ling to  come  to  fruiting  age.  Here,  as  with  other 
qualities,  there  is  great  variation,  and  it  is  pos- 

[230] 


BURBANK'S  WAY  WITH  TREES 

sible  for  the  experimenter  to  select  out  and  ac- 
centuate a  quality — in  this  case  precocious  bearing 
— by  the  usual  method  of  "line  breeding."  But 
at  best  patience  is  required  in  dealing  with  a 
plant  which  is  normally  of  such  slow  growth  as  a 
tree. 

OENAMENTAL   TEEES 

In  the  matter  of  stimulating  the  growth  of  a 
tree,  there  are  some  horticultural  tricks  that  are 
worth  remembering. 

Fundamental  among  these,  of  course,  is  the 
matter  of  preparation  and  cultivation  of  the  soil. 
Until  recently  a  good  many  orchardists  have  as- 
sumed that  it  is  useless  to  cultivate  the  soil  about 
trees.  But  now  it  is  well  known  that  a  tree  re- 
sponds as  readily  as  does  any  other  plant  to 
proper  treatment. 

Mr.  Burbank  tells  of  an  observation  that  fur- 
nishes striking  evidence  of  this.  He  once  observed 
the  rings  on  an  oak  tree  more  than  six  hundred 
years  old  that  had  just  been  felled,  and  he  noted 
that  at  a  certain  late  stage  of  its  development  the 
tree  had  suddenly  begun  to  grow  much  more  rap- 
idly than  had  been  its  wont  for  the  preceding  cen- 
turies. By  counting  the  rings,  he  determined  that 
the  new  growth  dated  from  the  year  1852.  In- 
quiry showed  that  this  was  the  time  when  the  land 
had  come  under  cultivation,  and  when  for  the  first 
time  the  soil  had  been  turned  and  rendered  porous 
by  the  plow. 

Thus  it  was  demonstrated  that  cultivation  of 
[231] 


LUTHER  BURBANK 

the  surface  soil  materially  affected  the  growth  of 
a  tree  already  more  than  five  centuries  old,  stimu- 
lating it  to  new  vigor  and  cellular  activity. 

This  observation  shows  that  even  the  oldest  tree 
is  not  beyond  reach  of  the  benefits  of  soil  culti- 
vation; and  the  experience  of  any  number  of 
orchardists  proves  the  immense  benefit  that  young 
trees  derive  from  such  cultivation.  It  is  probable 
that  the  foresters  of  the  future  will  cultivate  the 
soil  about  the  roots  of  their  timber-producing 
trees,  just  as  the  orchardist  already  cultivates  the 
soil  about  his  fruit  producers.  In  any  event,  the 
grower  of  ornamental  trees  and  shrubs  in  street 
and  dooryard  should  on  no  account  neglect  to  give 
his  proteges  the  benefit  of  rich  and  regular  culti- 
vation of  that  soil  for  a  number  of  feet  about  the 
trunk. 

Among  trees  other  than  bearers  of  fruit  and 
nuts  to  which  Mr.  Burbank  has  given  much  atten- 
tion are  the  magnolia,  Chinese  maidenhair  tree, 
and  numerous  conifers.  A  young  sequoia  ("big 
tree")  under  close  observation  is  among  the  most 
interesting  ornamental  trees  now  growing  in  his 
garden. 

Sometimes  it  happens  that  a  tree  that  has  a 
good  root  and  leaf  system  fails  to  grow  as  rap- 
idly as  it  might  because  it  becomes  "bark- 
bound."  Through  some  defect  in  the  quality  of 
its  bark,  the  trunk  is  constricted  and  its  growth 
prevented  somewhat  as  if  it  were  encased  in  an 
inelastic  artificial  jacket. 

Where  this  defect  exists,  it  may  readily  be 
[232] 


BURBANK  HYBRID  DAHLIAS. 

The  picture  gives  a  good  idea  of  the  range  of  variation  among 
the  material  on  which  Mr.  Burbank  is  now  working.  Here  are  fas- 
cinating possibilities  of  development  in  many  directions.  Some  very 
striking  and  popular  varieties  will  doubtless  result  from  the  further 
utilization  of  this  material  in  Mr.  Burbank's  gardens. 


BURBANK'S  WAY  WITH  TREES 

remedied  by  making  longitudinal  slits  with  a  knife 
at  intervals  about  the  trunk,  beginning  each  slit 
as  high  as  you  can  reach,  and  carrying  it  to  the 
very  root  of  the  tree. 

Mr.  Burbank  has  always  in  his  pocket  a  large 
jackknife  with  which  he  can  render  timely  aid  to 
any  tree  that  seems  to  his  keen  eye  to  be  suffering 
from  the  tightness  of  its  jacket.  In  the  experi- 
ment grounds  at  Sebastopol  you  may  see  many 
trees  that  have  been  treated  thus  in  the  past,  and 
most  effectively,  as  evidenced  by  the  broad  strips 
of  new  bark,  each  spreading  from  the  original 
track  of  the  knife  blade,  and  now  united  by  a 
visible  scar  with  the  old  bark  which  it  so  advan- 
tageously supplements. 

You  will  do  well  to  watch  your  trees  of  every 
kind  with  the  thought  in  mind  that  they  may  be 
bark-bound,  and  you  may  give  them  relief  and 
greatly  facilitate  their  growth  with  a  few  strokes 
of  your  knife  blade. 

Grafting  and  budding  are  of  course  processes 
that  require  more  skill.  The  details  as  to  these 
were  given  in  the  chapter  on  orchard  fruits.  I 
would  again  remind  the  reader,  however,  that  the 
process  of  grafting  may  be  applied  with  equal  ad- 
vantage to  trees  and  shrubs  of  almost  any  species, 
as  well  as  to  woody  vines.  You  may,  for  example, 
make  over  a  climbing  rose  by  grafting  it  with  buds 
taken  from  some  thrifty  vine.  Or  you  may  trans- 
form an  ill-shaped  and  weakly  shrub  into  a  sym- 
metrical and  vigorous  one  by  grafting  healthy 
scions  on  its  ill-nourished  branches. 

[233] 


LUTHER  BURBANK 

It  is  not  as  well  known  as  it  should  be  to  gar- 
deners and  orchardists  that  the  leaves  of  a  plant 
are  the  seat  of  the  essential  laboratory  in  which 
hydrogen  and  oxygen  and  carbon  are  compounded 
to  make  living  matter,  and  that  the  leaf  system 
of  tree  or  shrub  is  directly  responsible  for  the 
growth  of  the  root  system.  The  protoplasm  and 
starch  and  woody  fiber  that  go  to  make  up  the 
root  and  enable  it  to  grow  and  extend  its  ramifi- 
cations are  first  compounded  in  the  leaves,  and 
are  sent  down  through  the  cells  of  the  cambium 
layer  of  the  bark  in  return  for  the  watery  sap  that 
the  root  system  collects  as  raw  material  and  sends 
up  for  compounding  in  the  wonderful  leaf  labo- 
ratories. 

There  is,  in  short,  the  closest  interdependence 
between  leaf  system  and  root  system  in  the  case 
of  every  plant;  and  this  is  strikingly  shown  by 
observation  of  trees  and  shrubs.  If  a  tree  has  a 
healthy  leaf  system  you  may  be  sure  that  it  has  a 
good  root  system. 

We  have  noted  in  the  case  of  the  walnuts  how 
an  inherently  vigorous  root  system  of  a  hybrid 
variety  may  stimulate  the  development  of  the  leaf 
and  branch  system.  An  opposite  illustration  of 
the  co-operation  between  branch  and  root  is  given 
when  a  very  vigorous  scion  is  grafted  on  relatively 
weak  roots.  Here  the  vigor  of  the  top  may  give 
such  stimulus  to  the  root  system  that  it  keeps  pace 
with  the  growth  of  the  visible  parts  of  the  tree, 
far  surpassing  the  limits  it  would  have  attained 

[234] 


BURBANK'S  WAY  WITH  TREES 

had  it  been  left  in  partnership  with  its  original 
aerial  stem. 

A  striking  illustration  of  this  is  furnished  by  a 
splendid  elm  tree  that  grows  beside  Mr.  Bur- 
bank's  old  homestead  at  Santa  Eosa. 

This  fine  tree  is  in  reality  only  fifteen  or  sixteen 
years  old,  although  it  matches  in  size  other  elms 
that  are  approaching  the  half -century  mark.  The 
explanation  is  found  in  the  fact  that  the  tree  has 
grown  from  the  branch  of  a  natural  hybrid  elm. 
The  parent  tree,  which  Mr.  Burbank  declares  to 
be  the  largest  elm  he  ever  saw,  grew  near  his  old 
New  England  home.  When  visiting  his  old  home 
some  sixteen  years  ago,  he  cut  a  twig  from  this 
hybrid  tree  and  brought  it  with  him  to  California. 
The  twig  was  grafted  on  the  root  of  a  California 
elm,  being  implanted  only  a  few  inches  above  the 
ground,  so  that  the  scion  ultimately  furnished  the 
trunk  and  all  the  branches  of  the  tree.  Casually 
observing  this  wonderful  elm  to-day,  you  would 
never  suspect  that  it  is  not  growing  on  its  own 
roots ;  but  careful  inspection  shows  that  the  bark 
of  the  tree  on  one  side  is  of  slightly  different  tex- 
ture for  a  few  inches  from  the  ground,  and  that 
there  is  a  barely  visible  line  of  demarcation  where 
it  connects  with  the  contiguous  bark  of  the  main 
trunk  above. 

In  a  word,  everything  visible  except  these  few 
inches  of  bark  just  above  the  ground  level  is  hy- 
brid elm  of  New  England  ancestry;  whereas,  of 
course,  the  entire  root  system  is  California  elm. 
But  the  coalition  has  proved  a  most  happy  one,  as 

[235] 


LUTHER  BURBANK 

the  exceptional  size  and  vigor  of  the  tree  amply 
demonstrate. 

There  is  a  lesson  in  that  grafted  elm  that  any- 
one who  has  to  do  with  ornamental  trees  or  shrubs, 
or  for  that  matter  with  forest  trees,  may  advan- 
tageously take  to  heart. 


[236] 


PAET  III 

BURBANK'S  METHODS  AND  THE  HUMAN 
PLANT 


CHAPTER  XI 
THE  BREEDING  OF  MEN 

IT  is  worth  much,  by  plant  eugenics,  to  breed 
the  spines  from  the  cactus,  and  thus,  at  one 
stroke,  rid  the  world  of  a  plant  enemy  and 
give  it  a  new  plant  friend. 

But  it  is  worth  more,  who  shall  say  how  many 
times  more,  to  breed  strength  of  mind  or  strength 
of  body  into  a  child — to  breed  out  those  qualities 
which  might  make  the  child  a  menace  and  to 
breed  in  those  which  make  him  a  useful  citizen 
and  a  successful  individual. 

It  is  the  purpose  of  the  ensuing  chapters  to 
deal  with  the  subject  of  race  betterment  and  self" 
betterment  through  the  application  of  the  laws  of 
heredity  to  mankind — to  study  Luther  Burbank's 
amazing  success  in  plant  eugenics  with  an  eye 
toward  its  application  to  the  practice  of  human 
eugenics. 

Fitly  to  introduce  the  subject,  let  me  tell  the 
story  of  how,  through  the  practice  of  eugenics,  an 
obscure  German  bishop  became  the  father  of 
kings. 

It  is  a  story  with  all  the  elements  of  romance, 
but  it  is  sober  history. 

At  the  outset,  the  tale  concerns  seven  brothers 
who,  along  in  the  sixteenth  century,  inherited  a 

[239] 


LUTHER  BURBANK 

small  ducal  estate  on  the  borders  of  the  Black 
Forest.  The  estate  included  the  free  Hanseatic 
city  of  Liineburg,  and  was  large  enough  to  have 
some  significance  in  German  politics  if  undivided. 
But  the  brothers  realized  that  if  each  were  to 
claim  a  share  in  the  estate  its  divided  fragments 
would  have  little  importance  either  severally  or 
collectively. 

The  brothers  were  all  talented  and  ambitious 
men,  but  they  had  a  sense  of  family  obligation 
that  took  precedence  over  their  several  ambi- 
tions. So  they  held  a  family  conclave  and  de- 
cided that  only  one  of  their  number  should  marry. 
The  lot  fell  on  the  sixth  brother,  who  accordingly 
chose  a  wife  and  in  due  course  had  a  family  of 
children.  The  remaining  brothers  worked  and 
warred  in  the  interests  of  the  family  estate  with 
no  reward  except  the  consciousness  that  they  had 
added  prestige  to  the  family  name. 

The  children  of  the  sixth  brother  made  among 
themselves  the  same  compact  that  their  father 
and  uncles  had  made.  The  duty  of  transmitting 
the  family  name  devolved  upon  one  Ernest 
Augustus,  Bishop  of  Osnabriick.  In  that  day  an 
ecclesiastic  might  be  a  warrior  as  well,  and  the 
growing  influence  and  success  of  the  Bishop  of 
Osnabriick  enabled  him  to  win  for  his  wife  a  very 
extraordinary  woman,  Sophia  of  Palatine.  The 
son  born  of  this  union  inherited  the  original  es- 
tate with  sundry  accretions,  and  his  mother  be- 
lieved him  destined  for  great  things. 

But  a  brother  of  the  Osnabriick  Bishop  had 
[240] 


THE  BREEDING  OF  MEN 

broken  his  compact  and  also  married,  and  he  had 
a  daughter,  whose  advent  brought  consternation 
to  the  family.  Sophia  of  Palantine  never  forgave 
her  niece  for  being  born;  but  she  solved  the 
dilemma  by  marrying  her  own  son  to  said  offend- 
ing niece,  his  cousin.  So  the  family  interests  were 
again  united. 

Thus  it  appears  that  the  family  of  the  seven 
ambitious  brothers  was  a  dwindling  company  in 
the  two  generations  that  succeeded  their  compact, 
— and  expressly  because  of  their  compact.  In 
modern  terms  this  seems  a  case  of  race  suicide. 
But  it  may  properly  be  interpreted  in  a  yet  more 
modern  phrase. 

What  the  ambitious  brothers  and  their  suc- 
cessors had  done  was  to  practice  the  art  of  eugen- 
ics in  three  important  phases. 

They  had  (1)  restricted  the  number  of  de- 
scendants, through  preventing  the  birth  of  super- 
numerary children;  (2)  they  had  wisely  selected 
able  mates  for  the  procreating  member  of  the 
family;  (3)  and  they  had  concentrated  the  family 
estates  and  talents  by  judicious  inbreeding — that 
is  to  say,  by  the  union  of  cousins. 

Now  note  the  sequel  of  this  remarkable  prac- 
tice of  eugenic  principles.  The  son  of  the  erst- 
while Bishop  of  Osnabriick  and  his  brilliant  wife 
became  King  of  one  country  (George  I  of  Eng- 
land), and  their  daughter  became  Queen  of  an- 
other (Sophia  Charlotte  of  Prussia) .  Their  direct 
lineal  descendants  to-day  occupy  the  thrones  of 
England,  Germany,  Russia,  Denmark,  Norway, 

[241] 


LUTHER  BURBANK 

Greece,  and  numerous  minor  principalities.  As 
a  direct  sequel  of  that  conclave  of  the  seven  am- 
bitious brothers,  their  little  estate  became  the 
cradle  of  monarchs.  The  self-abnegation  prac- 
ticed by  the  six  brothers  bore  fruit  that  exalted 
their  family  from  the  control  of  a  petty  dukedom 
to  the  rank  of  kings  and  emperors. 

And  it  was  no  blind  chance  that  brought  about 
this  extraordinary  advancement.  It  was  the  con- 
scious application  of  laws  of  heredity  which  are 
followed  all  over  the  world  in  the  breeding  of 
domestic  animals,  but  which  have  been  for  the 
most  part  ignored  in  breeding  men.  To-day  the 
word  eugenics  is  heard  on  every  side  and  the  idea 
for  which  it  stands  is  in  the  air.  It  is  a  new 
word,  and  most  people  perhaps  suppose  that  the 
idea  is  also  new.  But  this  is  fallacious.  I  have 
cited  the  case  of  the  seven  brothers — a  perfectly 
authenticated  historical  case  which  will  further 
claim  our  attention  in  a  later  chapter — to  give 
tangible  illustration  of  the  fact  that  practical 
eugenics  as  applied  to  the  human  race  is  no  new 
art. 

The  new  thing  is  merely  that  nowadays  we 
should  begin  to  think  it  worth  while  to  apply  this 
art  to  humanity  in  general,  whereas  hitherto  it 
has  been  reserved  for  the  breed  of  kings. 

NEW  KNOWLEDGE  FKOM  PLANT  BEEEDING 

It  is  true,  however,  that  we  have  gained  in 
recent  years  a  great  deal  of  precise  knowledge  as 

[242] 


THE  BREEDING  OF  MEN 

to  the  laws  of  heredity  and  as  to  their  practical 
application.  In  particular,  it  has  come  to  be 
recognized  more  and  more  fully  that  the  same 
laws  of  heredity  apply  to  all  living  creatures,  and 
that  correct  inferences  may  be  drawn  from  obser- 
vation not  merely  of  lower  animals,  but  also  of 
plants,  as  to  the  application  of  the  laws  of  heredity 
to  humankind. 

This  is  peculiarly  fortunate  because  plants 
offer  in  many  ways  better  opportunities  for  ob- 
servation than  do  animals.  The  fact  that  plants 
may  be  grown  in  enormous  quantities,  often  ma- 
turing in  a  single  season,  gives  opportunity  for 
conducting  experiments  on  a  comprehensive  scale, 
and  sometimes  for  the  discovery  in  the  course  of  a 
few  years  of  laws  that  might  have  required  long 
periods  for  their  elucidation  had  observation  been 
confined  to  the  direct  breeding  of  the  human  race, 
or  even  to  the  breeding  of  the  most  prolific  do- 
mesticated animals. 

Everyone  is  aware  that  Luther  Burbank  has 
conducted  experiments  in  plant  breeding  on  a 
more  comprehensive  scale  than  any  other  experi- 
menter, and  that  he  has  operated  with  a  large 
number  of  individuals.  His  work  has  had  to  do 
with  members  of  the  vegetable  kingdom  of  every 
type,  and  he  has  ceaselessly  carried  out  his  experi- 
ments, seldom  having  less  than  three  thousand 
different  ones  under  way,  year  after  year,  for  a 
period  of  almost  half  a  century.  Naturally  he  has 
accumulated  a  vast  fund  of  information,  and  this 
has  now  become  available  to  the  general  public 

[243] 


LUTHER  BURBANK 

and  to  plant  breeders  through  the  official  publica- 
tion of  his  methods  and  results. 

I  have  had  opportunity  to  study  the  entire 
record  of  Mr.  Burbank 's  work  in  manuscript,  and 
to  confer  personally  with  Mr.  Burbank  himself  as 
to  all  its  details.  I  have  been  profoundly  im- 
pressed with  the  importance  of  this  work  not  only 
in  its  direct  bearings  on  horticulture  and  agricul- 
ture, but  in  its  application  to  the  breeding  of  the 
human  plant — a  subject,  it  may  be  added,  in  which 
Mr.  Burbank  himself  is  intensely  interested.  It 
has  seemed  worth  while  to  suggest  in  detail  the 
application  of  Mr.  Burbank 's  methods — guided  al- 
ways by  their  proved  results  in  the  vegetable 
world — to  the  question  of  the  improvement  of  the 
human  race,  with  particular  reference  always  to 
the  needs  of  the  individual  reader  in  everyday 
life. 

Such  an  attempt  will  be  made  in  the  following 
chapter.  I  have  thought  that  the  pertinency  of 
the  topic  and  its  practical  possibilities  might 
perhaps  be  emphasized  by  citing  at  the  outset  the 
authentic  anecdote  of  the  seven  brothers  who,  with 
rare  prevision,  more  than  two  centuries  ago,  fore- 
cast the  Burbank  methods  in  some  at  least  of  their 
most  important  applications,  and  in  so  doing  ex- 
alted their  family  to  the  foremost  place  not  merely 
in  one  nation,  but  in  many  nations.  With  this 
family  of  king  makers  we  have  no  further  present 
concern;  but  we  shall  have  occasion  to  examine 
their  pedigree  more  in  detail  in  another  connec- 
tion, since  it  gives  graphic  illustration  of  certain 

[244] 


THE  BREEDING  OF  MEN 

laws  of  heredity  tKat  are  of  cogent  interest  to  all 
of  us. 

BUEBANK  METHODS  IN  OUTLINE 

In  the  present  chapter  I  purpose  to  outline  the 
broader  principles  of  the  Burbank  methods,  with 
mere  suggestions  as  to  their  application  along 
various  lines  that  will  be  given  detailed  treatment 
in  successive  chapters. 

Mr.  Burbank  himself  has  very  explicitly  stated 
that  the  essence  of  his  method  is  rational  and  per- 
sistent selection.  In  a  comprehensive  experiment 
in  plant  development  he  (1)  selects  parent  forms 
to  be  mated,  and  then  (2)  selects  the  best  individ- 
uals among  the  progeny,  and  if  necessary  remates 
these  to  bring  desired  characters  into  the  heredi- 
tary strain.  When  the  right  combinations  have 
been  produced,  he  (3)  continues  to  select  the  best 
individuals,  generation  after  generation,  now 
practicing  inbreeding  instead  of  cross-breeding 
that  the  desired  traits  may  be  accentuated  by 
repetition. 

Casual  observers  of  Mr.  Burbank 's  work  have 
been  impressed  with  the  early  stages  of  this  line 
of  experimentation,  somewhat  to  the  oversight 
of  the  later  stages.  The  hybridizing  of  species 
brought  from  widely  different  regions  of  the  world 
is  a  somewhat  more  spectacular  process  than  the 
continued  inbreeding  or  "line  breeding"  of  a 
given  race,  since  the  latter  process  seems  to  con- 
sist of  nothing  more  than  the  selection  of  the  best 
individual  specimens  generation  after  generation. 

[245] 


LUTHER  BURBANK 

But  in  Mr.  Burbank's  opinion  this  process  of 
line  breeding  through  which  specialized  qualities 
are  accentuated  is  no  less  important  than  the 
earlier  process  of  cross-breeding;  and  in  making 
application  of  the  method  to  the  human  plant  we 
must  bear  this  constantly  in  mind. 

SELECTION    OF    PAEENTS 

In  the  great  majority  of  cases,  indeed,  nothing 
of  real  importance  could  be  accomplished  were 
the  experiment  carried  no  further  than  the  first 
mating  or  hybridizing  of  the  individuals  selected 
to  act  as  parents.  Yet,  on  the  other  hand,  right 
selection  here  is  the  condition  of  all  future  suc- 
cess. 

Some  of  Mr.  Burbank's  most  striking  results 
have  been  attained  through  the  hybridizing  of 
species  that  were  in  many  respects  widely  diver- 
gent. In  particular,  he  brought  together  species 
from  widely  separated  geographical  territories, 
and  thus  gave  opportunity  for  the  blending  of  di- 
versified racial  strains. 

Examples  in  point  are  furnished  by  the  vast 
numbers  of  experiments  with  members  of  the  race 
of  plums.  Almost  at  the  outset  of  his  experi- 
mental work  Mr.  Burbank  imported  plums  from 
eastern  Asia,  and  began  crossing  them  with  vari- 
ous species  of  plums  from  Europe  as  well  as  those 
indigenous  to  America.  Presently  he  had  hybrid 
races  on  his  experiment  farm  at  Sebastopol  that 

[246] 


THE  BREEDING  OF  MEN 

combined  the  racial   strains   of   practically   all 
known  species  of  plums  under  cultivation. 

More  than  that,  he  crossed  the  plum  with  the 
apricot,  producing  thereby  his  wonderful  new 
fruit,  the  plumcot. 

So  striking  have  been  the  results  of  this  mat- 
ing of  plums  of  diversified  characteristics  that 
more  than  sixty  new  varieties  of  plums,  prunes, 
and  apricots  have  been  introduced  by  Mr.  Bur- 
bank,  constituting  an  extraordinary  company  of 
fruits  that  are  revolutionizing  the  plum-growing 
and  prune-growing  industries  all  over  the  world. 
One-third  of  all  the  plums  shipped  from  Califor- 
nia are  now  Burbank  plums,  and  the  best  of  his 
new  varieties  are  of  such  recent  introduction  that 
they  have  not  as  yet  made  their  influence  felt,  as 
they  must  inevitably  do  in  the  course  of  the  com- 
ing decade. 

Other  illustrations  of  hybridizing  experiments 
through  which  Mr.  Burbank  has  produced  remark- 
able results — to  mention  a  few  almost  at  random 
— are  given  by  his  hybrid  races  of  blackberries 
and  raspberries,  including  the  Primus  berry,  the 
Phenomenal  berry,  the  white  blackberry,  and  the 
thornless  blackberries;  the  Paradox  and  Royal 
walnuts,  combining  the  traits  of  Persian  walnut 
with  those  of  the  California  black  walnut  in  one 
case,  and  of  the  eastern  species  of  black  walnut 
with  the  Calif ornian  in  the  other;  and  in  the 
Shasta  daisy,  which  combines  the  characteristics 
of  three  species  originally  inhabiting  Europe, 
America,  and  Japan,  respectively. 

[247] 


LUTHER  BURBANK 

AMEKICA — THE  BACIAL  MELTING-POT 

It  is  obvious  that  here  in  America  we  are 
bringing  together,  thanks  to  the  extraordinary  im- 
migration of  recent  years,  representatives  of  the 
human  species  of  many  races  and  from  all  regions 
of  the  globe.  In  the  nature  of  the  case,  these  new- 
comers will  ultimately  intermingle,  and  thus  there 
will  be  accomplished,  on  a  broader  and  more  com- 
prehensive scale,  some  such  blending  of  the 
strains  of  different  human  races  as  Mr.  Burbank 
has  accomplished  in  the  case  of  the  different 
races  of  plants. 

The  question  naturally  arises  as  to  whether  the 
remarkable  results  that  Mr.  Burbank  has  pro- 
duced in  developing  improved  races  of  plants  are 
likely  to  be  duplicated  in  the  case  of  the  human 
plant  here  in  America.  Offhand  it  might  seem 
that  such  should  be  the  case.  But  before  indulg- 
ing in  too  optimistic  an  augury  it  is  well  to  con- 
sider two  or  three  complications. 

In  the  first  place,  it  must  be  recalled  that  Mr. 
Burbank  imports  only  the  best  examples  of  the 
various  species  with  which  he  experiments.  He 
thus  breeds  from  selected  stock.  But  it  is  well 
known  that  a  large  proportion  of  the  immigrants 
that  have  come  to  the  United  States  in  recent 
years  are  not  the  best  representatives  of  their 
various  races.  On  the  contrary,  they  include  a 
large  proportion  of  inferior  representatives. 

Without  dwelling  at  length  on  the  matter  here, 
it  must  be  obvious  that  this  introduces  a  compli- 

[248] 


THE  BREEDING  OF  MEN 

cation  of  more  or  less  serious  import.  Mr.  Bur- 
bank  would  not  expect  to  improve  a  race  of  plants 
by  introducing  stock  of  an  inferior  type.  As  a 
general  proposition,  that  seems  axiomatic.  But, 
on  the  other  hand,  it  must  be  recalled  that  Mr. 
Burbank  frequently  finds  it  necessary  to  utilize  a 
stock  that  is  in  many  ways  inferior,  in  order  to 
take  advantage  of  some  one  desirable  quality  of 
that  stock. 

A  case  in  point  is  furnished  by  the  new  races 
of  wonderful  stoneless  plums  which  Mr.  Burbank 
developed  by  breeding  from  an  originally  wild 
plum  of  Europe  which  was  small  in  size,  and  so 
acrid  as  to  be  practically  inedible,  but  which  had 
the  essential  quality  of  bearing  a  kernel  with  only 
a  remnant  of  a  stone. 

This  might  very  justly  be  regarded  as  an  ab- 
normal plum,  and  as  a  very  perverted  or  retro- 
gressive and  altogether  worthless  example  of  its 
tribe.  Yet  its  one  quality  of  stonelessness — in  it- 
self an  abnormality  from  the  standpoint  of  plant 
economy — was  so  important  that  the  strains  of 
this  little  plum  have  been  combined  with  those  of 
a  great  variety  of  the  most  aristocratic  plums  in 
Mr.  Burbank 's  orchard.  And  it  has  been  found 
possible  to  breed  into  the  hybrid  progeny  the  good 
qualities  of  the  aristocratic  plums,  while  retain- 
ing the  quality  of  stonelessness  as  the  only  remi- 
niscence of  the  vulgar  and  perverted  ancestor. 

Is  it  not  possible,  then,  that  the  immigrants 
who  on  the  whole  seem  of  undesirable  type  may 
have  racial  characteristics  that  will  advantage- 

[249] 


LUTHER  BURBANK 

ously  blend  with  the  traits  of  the  American  race 
for  the  betterment  of  posterity? 

It  has  been  suggested,  for  example,  that  the 
Mediterranean  races  have  the  inherent  love  of 
music  and  the  arts  ingrained  in  their  racial  stock, 
and  that  this  artistic  sense  may  remain  as  a  per- 
manent endowment  of  their  descendants  in  Amer- 
ica when  their  less  desirable  physical  and  moral 
characteristics  have  been  bred  out  of  their  progeny 
by  mingling  with  the  better  strains  of  the  Ameri- 
can race,  somewhat  as  the  undesirable  qualities 
of  the  little  stoneless  plum  were  bred  out  of  their 
progeny  in  Mr.  Burbank's  gardens,  while  the  one 
desired  quality  of  stonelessness  was  retained. 

Obviously  this  possibility  must  modify  some- 
what our  verdict  as  to  the  possible  outcome  of  the 
great  mingling  of  races  that  is  taking  place  in 
America  to-day. 

BREEDING  FEOM  THE  UNFIT 

Let  it  be  recalled,  however,  that  the  prepon- 
derant influence  must  be  good  if  good  results  are 
to  be  attained.  We  cannot  hope  to  assimilate  too 
large  an  increment  of  foreign  blood.  More  than 
fourteen  hundred  thousand  immigrants  came  to 
the  United  States  in  1914.  Of  those  that  came 
from  southeastern  Europe  more  than  thirty-five 
per  cent  were  illiterate.  It  is  a  serious  question 
whether  the  American  stock  can  amalgamate  so 
high  a  percentage  of  foreign  elements  without 
deterioration. 

[250] 


THE  BREEDING  OF  MEN 

Another  complication  that  cannot  be  over- 
looked is  furnished  by  the  fact  that  the  less  desir- 
able members  of  the  population  are  observed  to 
be  far  more  prolific  than  are  the  superior  mem- 
bers. 

This  obviously  runs  counter  to  Mr.  Burbank's 
method  in  the  development  of  improved  races  of 
plants ;  for  it  goes  without  saying  that  he  chooses 
the  best  individuals  in  his  plant  colonies  for  cross- 
ing when  he  is  endeavoring  to  improve  a  given 
race.  Yet  here  again  there  are  qualifying  ele- 
ments. It  may  be  contended,  with  good  reason, 
that  the  American  race  is  a  highly  developed 
stock,  so  that  there  are  elements  of  good  in  even 
its  worst  examples.  One  can  never  be  sure,  then, 
that  the  progeny  even  of  individuals  of  undesir- 
able traits  may  not  show  reversion  to  the  better 
strains  of  their  ancestors. 

We  must  recall  that  every  individual  has  a 
vast  coterie  of  ancestors  who  in  the  aggregate 
represent  a  great  variety  of  traits.  You  can  prob- 
ably recall  your  four  grandparents,  for  example, 
and  a  moment's  reflection  will  convince  you  that 
they  differed  as  to  their  inherent  qualities.  And 
each  of  them  tended  to  transmit  his  or  her  quali- 
ties to  you,  their  common  descendant. 

Still  more  complicated  would  seem  your  heri- 
tage if  you  could  know  your  eight  great-grand- 
parents. And  when  you  reflect  that  the  genera- 
tion back  of  them  numbered  sixteen  individuals 
and  their  parents  thirty-two,  the  case  becomes 
still  more  complex. 

[251] 


LUTHER  BURBANK 

In  a  word,  your  ancestors  increase  in  a  geo- 
metrical ratio,  and  at  a  remove  of  only  ten  gen- 
erations they  number  more  than  one  thousand 
individuals.  According  to  the  most  fundamental 
law  of  heredity,  each  individual  tends  to  transmit 
all  of  his  or  her  traits,  and  a  moment's  reflection 
shows  that  the  ancestral  tendencies  that  are  strug- 
gling for  mastery  in  the  germ-plasm  of  any  indi- 
vidual are  multitudinous. 

It  is  obvious  that  many  of  the  traits  involved 
must  be  mutually  exclusive,  and  that  hence  any 
given  individual  must  have  almost  numberless 
latent  qualities  that  may  never  be  tangibly  re- 
vealed. 

We  shall  have  occasion  to  make  fuller  refer- 
ence to  this  aspect  of  the  subject  in  a  moment. 
Here  I  wish  merely  to  point  out  that  no  two  indi- 
viduals even  of  the  same  parentage  show  pre- 
cisely the  same  combination  of  characters,  and 
that  the  probability  of  bringing  out  any  given 
trait  obviously  increases  with  the  actual  number 
of  progeny. 

As  a  tangible  illustration,  Mr.  Burbank  has 
himself  called  attention  to  the  fact  that  he  was 
his  father's  thirteenth  child,  and  that  no  one  of 
the  dozen  children  who  preceded  him  manifested 
any  exceptional  aptitude  for  horticultural  pur- 
suits. There  are  numberless  cases  in  history 
where  the  man  of  genius  appears  as  a  later  mem- 
ber of  a  mediocre  fraternity.  So  we  must  recog- 
nize that  the  full  racial  opportunities  of  any  given 
strain  are  not  likely  to  be  realized  if  the  progeny 

[252] 


THE  BREEDING  OF  MEN 

are  restricted  to  two  or  three  individuals  in  a 
fraternity. 

At  first  sight,  then,  it  might  seem  that  the  en- 
thusiasts who  have  prated  about  race  suicide,  and 
urged  on  humanity  in  general  the  duty  of  having 
large  families,  were  justified.  And  indeed,  Mr. 
Burbank's  method  of  growing  vast  numbers  of 
seedlings,  in  order  to  select  the  best,  may  be  said 
to  be  corroborative. 

It  must  be  recalled,  however,  that  Mr.  Bur- 
bank  has  the  option  of  destroying  all  of  his  seed- 
lings, and  that  he  commonly  preserves  only  a  few 
among  the  thousands. 

Obviously  this  part  of  the  plant  breeder's  meth- 
ods cannot  be  applied  to  the  human  plant,  and 
hence  we  are  debarred  from  giving  indiscriminate 
approval  to  the  method  of  quantity  production  as 
applied  to  human  beings. 

What  we  are  justified  in  saying,  however,  is 
that  quantity  production  applied  to  the  better 
classes  of  the  community  would  be  highly  bene- 
ficial. It  should  be  remembered  that  Mr.  Bur- 
bank  applies  the  principle  of  quantity  production 
not  indiscriminately,  but  to  the  best  individuals. 
He  could  never  produce  the  improved  varieties 
for  which  he  is  famous  were  he  to  breed  only  from 
undesirable  members  of  the  colony,  even  though 
he  germinated  seeds  by  uncounted  millions. 


[253] 


LUTHER  BURBANK 

AID  FROM  GALTON  *S  LAW 

In  point  of  fact,  it  is  necessary,  in  order  to 
gain  a  clear  understanding  of  the  matter,  to  sup- 
plement what  was  just  said  about  the  multiple 
ancestry  of  each  individual  with  the  explicit  state- 
ment that  the  major  part  of  the  qualities  that  are 
likely  to  find  expression  in  any  given  case  has 
been  tangible  in  the  immediate  ancestors. 

According  to  an  estimate  made  by  the  late  Sir 
Francis  Galton,  and  hence  sometimes  spoken  of 
as  Galton 's  law,  each  individual  inherits  half  his 
tangible  traits  from  his  parents,  one-quarter  from 
his  grandparents,  one-eighth  from  the  great- 
grandparents,  and  so  on  in  decreasing  ratio. 

In  accordance  with  this  rule,  it  is  clear  that 
only  a  very  small  portion  of  the  tangible  traits  of 
any  individual  will  have  been  inherited  statistic- 
ally from  ancestors  more  remote  than  the  great- 
grandparents.  So  in  practice  we  are  fully  justi- 
fied in  saying  that  a  person  whose  immediate  an- 
cestors are  known  to  show  a  preponderance  of 
undesirable  traits  has  bad  heredity,  even  though 
it  can  be  shown  that  there  were  persons  of  the 
most  commendable  character  among  his  remote 
ancestors. 

In  practice,  then,  it  is  possible  for  Mr.  Bur- 
bank  to  determine  pretty  accurately  what  will  be 
the  main  characteristics  of  the  progeny  of  any 
given  cross  from  observation  of  the  parents  and 
grandparents  alone ;  yet  it  must  never  be  forgot- 
ten that  as  regards  some  quality  that  may  be 

[254] 


THE  BREEDING  OF  MEN 

vitally  important  there  may  be  reversion  to  a  re- 
mote ancestor. 

The  really  vital  question  is  whether,  in  prac- 
tice, there  is  any  definite  guide  as  to  this  mat- 
ter of  the  inheritance  from  remote  ancestors  of 
traits  that  are  not  manifest  in  the  immediate 
ancestors. 

Fortunately  this  question  may  now  be  answered 
in  the  affirmative.  The  new  knowledge  that  makes 
this  possible  was  gained  primarily  through  the 
study  of  inheritance  in  plants. 

Thus  Mr.  Burbank  early  discovered  that  when 
he  hybridized  two  plants  having  different  qual- 
ities the  progeny  of  the  first  filial  generation  were 
relatively  uniform  in  character,  but  that  their 
progeny  showed  a  very  strong  tendency  to  varia- 
tion, some  of  them  reverting  toward  one  parent 
and  others  toward  the  other,  and  still  others  show- 
ing a  new  combination  of  the  traits  of  the  parents. 

It  was  by  following  up  the  clews  thus  given 
that  Mr.  Burbank  was  able  to  make  many  of  his 
most  important  plant  developments. 

As  an  illustration,  Mr.  Burbank  crossed  a  par- 
tially thornless  bramble  that  had  been  discovered 
in  the  eastern  United  States  with  the  ordinary 
thorny  blackberry,  and  produced  a  race  of  hy- 
brids all  of  which  bore  thorns.  But  in  the  next 
generation  a  certain  number  of  the  progeny  were 
thornless ;  and  some  of  them  combined  with  thorn- 
lessness  the  good  qualities  of  fruit-bearing  of 
their  thorny  grandparent. 

On  the  same  principle,  Mr.  Burbank  produced 
[255] 


LUTHER  BURBANK 

his  stoneless  plums,  white  blackberries,  and  nu- 
merous other  new  plant  developments. 

MENDELIAN  HEREDITY 

The  discovery  that  second-generation  hybrids 
tend  thus  to  recombine  the  characteristics  of  their 
grandparents  in  new  combinations  has  been  made 
even  earlier  by  an  experimenter  whose  work  for 
the  time  being  was  ignored,  but  who  subsequently 
came  to  posthumous  fame  through  the  rediscovery 
of  his  work  about  the  beginning  of  the  present 
century.  This  was  the  Austro-Silesian  monk, 
Mendel.  He  had  not  only  made  independently 
the  discovery  that  had  meant  so  much  in  Mr.  Bur- 
bank's  work,  but  he  had  followed  it  out  with 
numerical  computations  that  gave  him  a  very 
definite  notion  as  to  the  exact  way  in  which  the 
divergent  traits  of  any  given  pair  of  parents 
would  be  combined  in  their  descendants. 

Mendel's  work  was  chiefly  done  with  the  gar- 
den pea,  and  he  dealt  with  qualities  that  are 
mutually  exclusive — large  size  versus  small  size, 
for  example,  in  the  case  of  the  pea,  or  yellow  pods 
versus  green  pods,  or  pink  flowers  versus  white 
flowers. 

To  state  the  simplest  case,  Mendel  found  that 
when  a  tall  race  of  peas  is  crossed  with  a  short 
race  the  progeny  are  all  tall;  but  the  quality  of 
shortness,  although  for  the  moment  suppressed,  is 
not  lost,  but  reappears  in  about  one  in  four  of 
the  progeny  of  the  next  generation. 

[256] 


A  GIGANTIC  BULB 

The  bulb  that  Mr.  Burbank  holds,  is  a  hybrid  specimen  produced  by 
crossing  the  crinum  and  the  amaryllis.  This  specimen  has  not  shown 
flower-bearing  qualities  commensurate  with  its  size,  and  it  is  about  to  be 
discarded. 


THE  BREEDING  OF  MEN 

Mendel  spoke  of  tallness  as  "  dominant  "  in  the 
case  of  the  pea  and  of  shortness  as  "  recessive, " 
and  these  terms  are  so  convenient  that  they  have 
passed  into  current  usage.  The  essential  thing  is 
that  the  recessive  trait,  if  its  elements  are  present 
in  the  germ-plasm  of  an  individual,  will  inevitably 
reappear  in  a  percentage  of  the  offspring  of  that 
individual  under  certain  conditions;  and  it  has 
been  found  that  this  fact  is  highly  important  from 
the  human  standpoint,  inasmuch  as  there  are  cer- 
tain human  traits  that  show  the  phenomena  of 
dominance  and  recessiveness  in  inheritance. 

This  is  particularly  true,  for  example,  with 
defects  of  the  brain  and  nervous  system  which 
may  manifest  themselves  in  subnormal  mentality. 

There  is  a  growing  body  of  evidence  to  show 
that  mental  normality  is  dominant  to  mental  ab- 
normality, in  the  Mendelian  sense  of  the  word. 
Hence,  when  a  perfectly  normal  individual  is 
mated  with  one  of  subnormal  mentality,  the  off- 
spring will  probably  be  normal ;  but  these  normal 
offspring,  carrying  the  mental  defect  as  a  reces- 
sive trait,  if  mated  with  other  individuals  of  simi- 
lar heritage,  may  have  progeny  about  one-quarter 
of  whom  are  of  defective  mentality. 

As  an  illustrative  example,  I  may  cite  a  case 
that  came  very  recently  under  my  observation.  I 
was  asked  to  examine  a  boy  of  ten  who  was  ob- 
viously abnormal,  and  who  on  examination  proved 
to  be  feeble-minded.  His  parents  were  not  only 
normal  mentally,  but  were  both  persons  of  excep- 
tional ability,  the  father  being  a  professor  in  a 

[257] 


LUTHER  BURBANK 

leading  university,  and  the  mother  a  woman  of 
unusual  culture  and  of  a  thoroughly  common- 
sense  type  of  mind.  Inquiry  revealed  the  fact, 
however,  that  in  the  families  of  both  father  and 
mother  were  members  who  were  mentally  un- 
sound. 

This  taint  of  defective  mentality  was,  then,  a 
recessive  trait  in  the  germ-plasm  of  both  parents ; 
so  it  was  almost  a  foregone  conclusion  that  about 
one  in  four  of  their  progeny  would  show  some 
form  of  mental  abnormality.  In  point  of  fact 
there  were  three  children,  two  of  whom  were 
sound  of  mind  and  of  unusual  ability,  the  third 
being  the  defective  child  just  referred  to. 

It  goes  without  saying  that  this  man  and 
woman,  however  well  suited  for  each  other  in  all 
other  regards,  should  have  been  debarred  from 
marrying  by  the  fact  that  they  both  carried  latent 
strains  of  mental  abnormality  in  their  heredity. 
But  it  is  only  in  the  most  recent  times  that  any- 
one has  understood  the  danger  involved  in  such 
a  union. 

COUSIN   MAKKIAGES 

Now  that  we  have  a  clearer  insight,  it  is  ob- 
vious that  such  a  case  as  that  just  cited  is  pre- 
cisely comparable  to  what  takes  place  when  Mr. 
Burbank  endeavors  to  fix  and  accentuate  a  qual- 
ity by  what  he  commonly  speaks  of  as  line  breed- 
ing— that  is  to  say,  by  the  union  of  individuals 
having  the  same  hereditary  tendencies. 

[258] 


THE  BREEDING  OF  MEN 

When,  for  example,  Mr.  Burbank  discovered 
a  specimen  of  the  wild  California  plant  called 
heuchera,  or  "wild  geranium,"  that  had  a 
tendency  to  crinkle  the  edges  of  the  leaves,  he 
transplanted  this  specimen  to  his  garden  and  care- 
fully inbred  its  progeny  generation  after  genera- 
tion, selecting  always  the  ones  that  showed  the 
tendency  of  malformation  of  leaves,  until  pres- 
ently he  had  a  new  race  of  heuchera  with  the 
most  curiously  convoluted  leaves. 

He  could  not  have  produced  this  result  had  he 
not  interbred  individuals  that  had  the  peculiarity 
of  their  heredity. 

And  this,  indeed,  is  the  typical  method,  as  al- 
ready suggested,  by  which  Mr.  Burbank  fixes  and 
accentuates  a  character,  once  that  character  has 
manifested  itself.  It  was  thus,  for  example,  that 
the  scented  callas  and  verbenas  and  petunias 
were  produced ;  also  the  improved  Burbank  varie- 
ties of  almost  numberless  other  flowers,  fruits, 
and  vegetables. 

Of  course,  in  the  case  of  the  human  parents 
just  referred  to,  the  character  contained  in  their 
germ-plasm  was  one  which  they  desired  to  see 
eliminated,  not  perpetuated.  But  nature  is  quite 
impartial  in  the  application  of  her  laws  of  hered- 
ity. The  same  manner  of  transmission  applies  to 
desirable  traits  and  undesirable  ones.  Indeed,  it 
may  be  said  that  from  the  standpoint  of  plant 
economy  some  of  the  same  qualities  that  make 
Mr.  Burbank 's  new  fruits  and  flowers  most  desir- 
able are  abnormalities.  A  double  flower,  for  ex- 

[259] 


LUTHER  BURBANK 

ample,  is  much  less  well  adapted  to  propagate  its 
kind  than  a  single  one.  Yet  from  the  standpoint 
of  the  plant  developer  the  double  condition  is  de- 
sirable, as  it  enhances  the  beauty  of  the  flower. 

In  the  case  of  the  human  subject,  however, 
the  traits  are  adjudged  by  another  standard,  and 
are  considered  desirable  only  if  they  conduce  to 
the  welfare  of  the  individual  and  the  race.  So  we 
are  usually  concerned  with  the  exclusion  of  un- 
desirable qualities,  and  it  is  these  that  have 
hitherto  been  chiefly  studied  by  students  of  hered- 
ity. But  the  fact  that  some  at  least  of  these 
qualities  are  transmitted  along  Mendelian  lines 
gives  clews  that  are  invaluable. 

The  analogy  with  plant  experiments  shows  how 
a  defective  trait  that  acts  as  a  recessive  factor  in 
inheritance — any  mental  deficiency  or  suscepti- 
bility to  tuberculosis — may  be  ingrained  in  a  fam- 
ily and  result  disastrously.  But,  contrariwise, 
this  same  knowledge  points  the  way  to  the  elimi- 
nation of  such  a  defective  strain. 

Just  as  Mr.  Burbank  could  not  fix  the  abnor- 
mal quality  of  his  wild  geranium  leaf  without  in- 
breeding, so  the  defective  quality  in  the  human 
subject  is  not  likely  to  be  fixed  unless  a  person 
having  the  defect  mates  with  another  having  a 
similar  defect. 

And  this  gives  us  a  clew  to  a  full  understand- 
ing of  the  question  of  cousin  marriage,  regarding 
which  there  has  been  a  good  deal  of  difference 
of  opinion  among  students  of  heredity  in  the  past. 
In  the  light  of  the  new  knowledge  it  would  appear 

[260] 


THE  BREEDING  OF  MEN 

that  there  is  no  necessary  danger  in  such  unions 
provided  there  is  no  defective  strain  in  the  family. 

On  the  contrary,  a  desirable  quality,  even 
genius  itself,  may  be  thus  accentuated,  as  we  saw 
illustrated  in  the  case  of  the  family  of  the  seven 
brothers. 

If,  however,  a  defective  strain  exists,  the  mar- 
riage of  cousins  brings  together  the  two  defective 
elements  in  precisely  the  way  best  suited  to  make 
them  tangible  in  the  offspring. 

The  practical  lesson  is  that  if  there  is  a  strain 
of  mental  defect  or  of  susceptibility  to  tubercu- 
losis— to  name  only  two  important  conditions — 
in  your  family,  it  would  be  unwise  for  you  to 
marry  a  cousin,  although  such  a  union  might 
otherwise  be  not  undesirable.  The  same  objection 
applies  to  the  union  of  individuals  who  have  the 
same  defect. 

Thus  it  appears  that  the  new  knowledge  of 
heredity  does  not  necessarily  tell  whom  you  should 
marry,  but  may  tell  whom  you  should  not  marry. 
It  is  believed  that  a  knowledge  of  Mendelian 
heredity  will  serve  as  a  guide  to  intelligent  cou- 
ples in  future,  and  that  the  happiness  of  the  in- 
dividual and  the  welfare  of  the  race  will  thereby 
be  vastly  enhanced. 

A  fuller  treatment  of  this  aspect  of  the  subject 
will  of  course  be  given  in  a  later  chapter. 


[261] 


CHAPTER  XII 

THE  LAWS  OF  HEREDITY— THEIR 

DEFINITE  MEANING  AND 

INTERPRETATION 

IT  is  traditional  that  one  cannot  gather  grapes 
from  thorns  nor  figs  from  thistles.  The  tra- 
dition embodies,  by  implication,  the  essence 
of  the  great  central  laws  of  heredity.  This  law  is 
stated  even  more  explicitly  in  the  colloquial 
phrase  "like  produces  like.'7 

The  sum  and  substance  of  the  matter  is  that 
each  and  every  living  organism,  be  it  vegetable  or 
animal,  tends  to  reproduce  its  own  kind,  and  if  we 
would  get  at  the  fundamental  laws  of  heredity  we 
have  but  to  follow  up  the  clew  that  this  familiar 
fact  gives. 

We  may  see  the  principle  illustrated  to  best 
advantage,  perhaps,  if  we  consider  the  lowly 
single-celled  organisms,  of  which  bacteria  furnish 
a  familiar  type.  These  creatures,  observed  under 
the  microscope,  are  seen  to  multiply  by  division, 
a  single  bacterium  splitting  to  form  two  bacteria, 
each  of  which  presently  grows  to  the  dimensions 
of  the  original  parent,  and  then  repeats  the  proc- 
ess of  division. 

Such  a  process  of  multiplication  obviously 
[262] 


THE  LAWS  OF  HEREDITY 

passes  on  the  substance  of  an  organism  to  its 
descendants  in  so  definite  and  tangible  a  way  that 
there  is  nothing  mysterious  at  all  about  the  ob- 
served fact  that  children  are  closely  comparable 
to  the  parent.  It  is  inconceivable  that  they  should 
be  otherwise  under  the  circumstances.  The  basal 
fact  of  heredity,  then,  observed  thus  as  it  were  at 
its  source,  seems  not  in  the  least  mysterious,  but 
a  mere  matter  of  fact. 

When  we  reflect  that  complex  higher  organisms 
are  made  up  of  groups  of  cells  aggregated  and 
differentiated  to  perform  specialized  functions, 
and  that  all  growth  takes  place  through  cell  divi- 
sion, it  will  be  clear  that  the  distinction  between 
the  single-celled  organism  and  the  complex  higher 
organism  is  not  as  radical  as  might  at  first  thought 
appear.  Each  individual  even  of  the  highest 
forms  of  life,  including  man  himself,  begins  ex- 
istence as  a  single  cell  and  grows  and  develops 
only  through  the  countless  redivisions  of  that 
cell. 

There  is,  however,  a  highly  important  modifi- 
cation to  be  noted  in  the  fact  that  the  cells  of  the 
higher  organism  become  differentiated  into  di- 
vergent groups,  capable  of  performing  different 
functions.  And,  from  our  present  standpoint,  the 
thing  to  be  particularly  noted  is  that  the  tissue 
serving  the  purpose  of  reproduction  of  the  species 
is  segregated;  and  that  this  segregation  takes 
place,  in  the  case  of  higher  animals,  at  a  very 
early  stage  of  the  embryonic  development  of  the 
individual. 

[263] 


LUTHER  BURBANK 

THE  CONTINUITY  OF  THE  GERM-PLASM 

The  full  significance,  from  the  standpoint  of 
heredity,  of  this  segregation  of  the  germ-plasm 
has  been  appreciated  only  within  comparatively 
recent  years.  It  was  not  until  Professor  August 
Weismann  made  special  studies  in  this  field,  about 
thirty  years  ago,  that  the  subject  prominently  at- 
tracted the  attention  of  biologists. 

Weismann  had  been  struck  by  the  fact  that 
single-celled  organisms,  owing  to  the  character  of 
their  reproduction  by  division,  are,  as  he  phrased 
it, '  '  potentially  immortal. ' '  They  do  not  normally 
die,  but  rejuvenate  themselves  by  division,  a  given 
individual  becoming  two,  and  these  two  presently 
becoming  four,  and  so  on  in  an  unending  geomet- 
rical progression,  in  which  the  descendants  of  any 
generation  whatever  might  be  regarded  as  repre- 
senting the  divided  substance  and  personality  of 
the  original  ancestor. 

Weismann  made  application  of  this  thought 
to  the  cells  constituting  the  germ-plasm  of  the 
higher  organisms.  These,  he  said,  pass  on  their 
substance  and  hence  their  potentialities  from  gen- 
eration to  generation  much  as  does  the  protozoan ; 
and  this  fact  of  the  continuity  and  virtual  im- 
mortality of  the  germ-plasm  furnishes  the  simple 
and  obvious  explanation  of  the  observed  facts 
of  hereditary  transmission  of  qualities  from  one 
generation  to  another. 

In  each  new  generation  a  certain  number  of 
cells  are  differentiated  to  form  body-plasm,  and 

[264] 


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THE  LAWS  OF  HEREDITY 

ultimately  develop  to  produce  the  entire  organism 
with  its  varied  members  and  bodily  organs;  but 
the  remaining  and  essential  portion  of  the  germ- 
plasm  maintains  its  integrity  as  germ-plasm,  di- 
viding to  produce  cells  of  its  own  kind,  even  as  a 
bacterium  or  an  ameba  divides,  and  constituting 
an  unbroken  series  of  germ-cells  linking  the 
earliest  ancestor  of  any  line  with  the  remotest 
descendant. 

Parent  and  child  are  thus  sprung  from  the 
same  germinal  stream,  and  in  the  broadest  view 
they  are  not  to  be  regarded  as  mother  and  daugh- 
ter, but  rather  as  sisters  of  the  same  fraternity. 

The  child  has  the  qualities  and  characteristics 
of  its  parent  not  through  any  occult  law  of  trans- 
mission, but  because  they  both  draw  their  qualities 
from  the  same  germinal  stream — the  perennial 
stream  of  the  ancestral  germ-plasm. 

It  is  important  to  get  this  idea  of  the  continuity 
of  the  germ-plasm  clearly  in  mind,  for  it  furnishes 
the  clew  to  a  clearer  understanding  of  the  mys- 
teries of  heredity  than  would  otherwise  be  pos- 
sible. 

MODIFICATION  OF  THE  GEEM-PLASM 

It  must  at  the  same  time  be  clearly  borne  in 
mind,  however,  that  the  stream  of  ancestral  germ- 
plasm,  which  thus  serves  as  the  carrier  of  heredi- 
tary capacities  from  generation  to  generation,  is 
not  entirely  beyond  the  reach  of  external  influ- 
ence, and  does  not  remain  absolutely  unmodified 
throughout  indefinite  periods  of  time. 

[265] 


LUTHER  BURBANK 

Even  the  bacterium  changes  its  constitution 
somewhat  in  response  to  the  conditions  of  temper- 
ature and  nutriment  in  which  it  finds  itself.  By 
altering  the  medium  and  thus  the  food  in  which 
bacteria  grow,  it  has  been  found  possible  to 
change  their  constitution  so  markedly  that  viru- 
lent types  become  relatively  innocuous  in  the 
course  of  a  few  generations.  Recent  experiments 
suggest  that  the  same  thing  may  be  accomplished 
by  treating  bacteria  with  ultra-violet  rays,  not 
sufficiently  intense  to  destroy  their  vitality. 

In  a  word,  very  marked  modifications  in  the 
constitution  of  the  single-celled  organism  may  be 
produced  by  altered  conditions  of  its  tangible 
environment. 

And  these  modifications  are,  as  a  matter  of 
course,  passed  on  to  the  descendants  of  the  bac- 
terium, inasmuch  as  these  descendants  constitute, 
essentially,  portions  of  the  parent  form. 

Exactly  the  same  thing  applies  to  the  allied 
process  of  reproduction  of  the  germ-plasm  cells  of 
the  higher  organism.  Modified  conditions  of  en- 
vironment— changed  conditions  of  temperature 
and  of  nutrition — may  in  some  cases  modify  them, 
and  such  modifications  will  be  transmitted  to  their 
offspring. 

It  is  obvious  that  if  such  were  not  the  case 
there  could  be  no  change  in  the  structure  or  con- 
stitution of  any  given  line  of  organisms  from  the 
remotest  ancestor  to  the  most  recent  descendant, 
inasmuch  as  the  hereditary  and  permanent  altera- 
tions of  the  body-plasm  are  contingent — accord- 

[266] 


THE  LAWS  OF  HEREDITY 

ing  to  hypothesis — upon  modifications  of  the 
germ-plasm. 

But  a&  nowadays  it  is  fully  admitted  that  all 
forms  of  life  have  undergone  change  in  the  past — 
higher  forms  evolving  from  lower  ones  through 
modification — it  is  obvious  that  each  stream  of 
ancestral  germ-plasm  must  have  been  more  or  less 
subject  to  influences  that  modify  it. 

As  much  as  this  at  least  is  admitted  by  every 
biologist,  whatever  his  view  toward  the  allied 
question  of  the  heritability  of  modifications  that 
affect  the  body-plasm  of  an  individual  rather  than 
the  germ-plasm — a  question,  by  the  way,  that  will 
claim  our  attention  in  another  connection,  but 
which  need  not  becloud  our  vision  at  the  moment. 

It  must  be  understood,  however,  that  the  modi- 
fications that  can  be  introduced  in  the  germ- 
plasm  in  any  given  organism,  through  whatever 
environmental  changes,  are  relatively  slight  as 
contrasted  with  the  totality  of  qualities  of  that 
germ-plasm. 

It  is  inconceivable,  for  example,  that  the  germ- 
plasm  of  a  brier  should  be  so  modified  that  its 
offspring  will  be  bearers  of  grapes;  or  that  the 
germ-plasm  of  a  thistle  shall  become  so  trans- 
formed that  the  body-plasm  sprouting  from  it  in 
the  next  generation  shall  produce  figs — to  revert 
to  the  familiar  illustration  with  which  we  set 
out. 

To  be  sure,  the  vine  that  bears  grapes  and  the 
tree  that  bears  figs  were  doubtless  originally  as 
different  from  their  present  states  as  they  still  are 

[267] 


LUTHER  BURBANK 

different  from  thorns  and  thistles,  but  the  gradua- 
tions of  modification  through^  which  the  trans- 
formation has  been  brought  about  were  infinitesi- 
mal in  any  pair  of  generations  and  have  produced 
their  effects  only  through  the  cumulative  influ- 
ence of  myriads  of  generations. 

If  really  radical  transformations  could  be 
wrought  in  the  germ-plasm  of  any  organism  in  a 
brief  period  of  time,  the  whole  organic  world 
would  be  topsy-turvy  and  there  would  be  no  laws 
of  heredity  to  discuss — at  least  those  laws  would 
be  something  quite  different  from  what  they  are. 

Let  us,  then,  supplement  our  idea  of  the  con- 
tinuity of  the  germ-plasm  with  the  thought  that 
this  germ-plasm  may  be  modified  from  time  to 
time,  but  that  the  amount  of  modification  permis- 
sible within  any  limited  period  is  infinitesimal  in 
comparison  with  the  sum  total  of  the  qualities  of 
the  germ-plasm  itself ;  which  qualities,  it  may  be 
added,  represent  the  aggregate  influence  of  past 
environments  throughout  vast  and  incomprehen- 
sible periods  of  time. 

Luther  Burbank  has  a  capital  phrase,  to  the 
effect  that  "heredity  is  the  sum  of  all  past  envi- 
ronments." The  import  of  the  phrase  becomes 
perhaps  clearer  if  we  think  of  it  in  connection  with 
this  picture  of  the  ancestral  germ-plasm — the 
tangible  and  definite  series  of  cells  directly  link- 
ing every  individual  of  any  generation  with  the 
entire  series  of  its  direct  ancestors. 


[268] 


THE  LAWS  OF  HEREDITY 

CHICKEN   VERSUS   EGG 

When  we  consider  the  germ-plasm  in  this  light, 
its  transmission  of  hereditary  qualities  seems  in 
a  sense  simple  and  unavoidable. 

But  if  we  consider  the  matter  a  little  more  at- 
tentively it  will  appear  that  the  germ-cell  retains 
no  small  measure  of  mysteriousness.  We  agreed 
that  there  was  nothing  mysterious  about  the  fact 
that  the  single-celled  organism — say  the  bac- 
terium— transmits  its  qualities,  inasmuch  as  its 
entire  body  is  bisected.  But,  although  we  have 
likened  the  germ-cells  to  a  single-celled  organism 
— which  in  point  of  fact  it  externally  resembles — 
we  cannot  proceed  far  without  noting  the  vital 
fact  that  the  germ-cell  carries  the  potentialities 
not  merely  of  other  germ-cells  like  itself,  but  of 
body-cells  in  endless  profusion  that  go  to  make  up 
the  complex  organism — let  us  say  of  a  tree  or  of 
a  man. 

How  is  it  conceivable  that  a  germ-cell  of  mi- 
croscopic size  shall  carry  forward  such  poten- 
tialities, and  carry  them  so  definitely  that  they 
predetermine  with  absolute  accuracy  the  form  of 
every  leaf  on  the  tree,  or  the  color  of  the  eyes,  the 
complexion,  and  the  mental  qualities  of  the  man? 

As  to  that,  no  one  can  give  a  really  valid  an- 
swer. That  the  germ-cell  does  convey  these  po- 
tentialities is  familiar  matter  of  fact.  How  it  can 
convey  them  seems  at  first  thought  absolutely  in- 
comprehensible. But  philosophers  in  all  ages 
have  puzzled  over  the  matter,  and  there  have  been 

[269] 


LUTHER  BURBANK 

various  theories  put  forward  in  attempted  ex- 
planation. 

There  was,  for  example,  a  theory  that  gained 
popularity  a  few  centuries  ago,  to  the  effect  that 
all  the  individuals  that  are  to  descend  (in  succes- 
sive generations)  from  any  given  germ-cell  exist 
preformed  in  that  cell.  In  a  figurative  sense, 
this  fact  might  be  said  to  be  axiomatic.  But  the 
advocates  of  the  theory  declared  that  it  was  true 
in  a  literal  sense  also. 

Out  of  this  thought-tangle  arose  the  famous 
quibble  as  to  which  first  existed — the  chicken  or 
the  egg. 

Of  course  there  was  not  the  slightest  scintilla 
of  proof  of  any  such  mysterious  ingulfing  of  in- 
finite numbers  of  future  organisms  in  the  micro- 
scopic cell.  And,  equally,  of  course,  the  theory 
did  not  long  persist. 

MECHANISM   OF   THE   GEKM-CELL 

Nevertheless,  it  is  interesting  to  attempt  to 
visualize  conditions,  even  when  the  conditions 
themselves  lie  beyond  the  limit  of  microscopic 
vision.  And  when  the  germ-cell  is  thus  visualized, 
one  is  forced  to  conceive  of  it  as  made  up  of  in- 
finitesimal particles  of  matter  that  in  some  way 
carry  preformed  the  future  organism  that  may 
grow  from  it.  No  one  nowadays,  however,  sup- 
poses that  this  aggregation  of  infinitesimal  par- 
ticles in  the  germ-cell  represents  a  replica  of  an 
adult  organism.  The  conception  is  merely  that 

[270] 


THE  LAWS  OF  HEREDITY 

there  are  particles  of  matter  to  represent  each 
tissue  or  organ  of  the  future  organism,  and  that 
these  are  in  some  way  so  mutually  disposed  as  to 
predetermine  the  future  relations  of  the  organs 
that  will  develop  from  them. 

The  modern  physicist  makes  accurate  studies 
of  the  sizes  of  molecules  and  atoms  and  of  their 
numbers  in  a  particle  of  matter  comparable  to 
the  smallest  germ-cell,  that  enables  us  to  compre- 
hend how  very  complex  a  structure  this  germ-cell 
may  really  be. 

He  tells  us,  for  example,  that  there  lies  at  the 
heart  of  the  germ-cell  a  nucleus  of  infinitesimal 
size,  yet  his  microscope  reveals  various  physical 
structures  within  the  nucleus  which  he  calls 
"chromosones"  because  they  are  readily  colored 
by  stains.  He  believes  that  these  "chromosones" 
have  to  do  with  the  transmission  of  characters, 
yet  he  knows  that  they  themselves  must  be  enor- 
mously complex ;  and  he  makes  calculations  which 
show  that  these  chromosones,  infinitesimal  though 
they  be,  are  made  up  of  millions  of  atoms.  The 
very  smallest  particle  of  matter  that  the  micro- 
scope reveals  is  estimated  to  contain  "many  times 
twenty  billion  atoms. " 

So  the  germ-cell  may  be  in  reality  an  enor- 
mously complex  organism,  containing  thousands 
of  particles,  each  one  of  which  is  made  up  of  mil- 
lions of  atoms. 

Such  a  computation,  while  it  to  some  extent 
satisfies  the  mind  as  giving  tangibility  to  the  sub- 
ject, does  not  in  any  proper  sense  fathom  the 

[271] 


LUTHER  BURBANK 

mystery.  It  shows  us  that  the  germ-cell  may  be 
indefinitely  complex ;  but  it  does  not  explain  to  us 
how  its  aggregated  particles — which  themselves 
are  all  grouped  within  the  compass  of  a  single 
microscopic  cell — can  definitely  determine  the  size 
and  form  and  color  and  peculiarities  of  the  future 
organism  into  which  that  cell  may  grow. 

In  a  word,  the  ultimate  mystery  of  the  trans- 
mission of  traits  through  heredity,  which  is  in- 
volved in  the  mystery  of  every  higher  organism, 
is  an  unsolved  enigma  which  challenges  the  pro- 
founder  insight  of  the  future  investigator.  Here 
we  must  be  content  to  take  the  facts  of  heredity 
for  granted,  and  to  point  out  the  modus  operandi 
of  inheritance  without  attempting  to  fathom  its 
precise  meanings. 

In  a  word,  the  mystery  of  heredity  is  linked 
with  the  mystery  of  life  itself,  and  the  two  mys- 
teries await  a  common  solution. 

THE  FACTS  OF  HEEEDITY 

The  facts  of  heredity,  considered  in  detail, 
seem  enormously  intricate,  yet  they  may  be  re- 
duced to  a  few  comparatively  simple  general 
classes.  Indeed,  the  broad  fundamental  fact  that 
each  organism  tends  to  reproduce  its  qualities  in 
its  offspring  may  be  said  to  be  the  one  all-com- 
passing fact  that  includes  every  minor  detail  of 
hereditary  transmission. 

The  full  meaning  of  this  great  central  fact  of 
heredity  was  perhaps  most  comprehensively  in- 

1  272  ] 


THE  LAWS  OF  HEREDITY 

terpreted  by  Professor  Ernst  Haeckel,  when  he 
formulated  his  so-called  "gastraea"  theory,  in 
accordance  with  which  each  individual  organism 
tends,  in  the  course  of  its  development,  to  repro- 
duce the  ancestral  forms  through  which  the  race 
has  passed  in  its  evolutionary  progress. 

Thus  the  human  embryo  is  at  first  a  single 
cell  and  it  passes  in  its  embryonic  development 
through  stages  in  which  it  resembles  such  lower 
orders  as  fish  and  amphibia  and  lower  mammals 
before  it  assumes  the  proportions  and  character- 
istics of  the  human  being. 

The  characters  are,  of  course,  slurred  over,  and 
the  reproduction  of  racial  history  is  at  best  a 
blurred  and  epitomized  one,  yet  the  fact  that  the 
embryo  does  pass  through  such  varied  transfor- 
mations, and  that  these  at  least  roughly  outline 
the  racial  history,  is  a  highly  interesting  and  im- 
portant one,  and  may  be  said  to  exemplify  the 
fundamental  law  of  heredity  in  the  most  com- 
prehensive way. 

It  is  obviously  a  mere  detail  within  this  gen- 
eral law  that  an  adult  individual  should  some- 
times develop  a  characteristic  or  an  anomaly  of 
some  organ  or  tissue  at  the  same  age  when  the 
same  characteristic  or  anomaly  was  manifested 
by  a  parent.  Examples  in  point  are  furnished  by 
those  not  familiar  cases  in  which  a  cancerous 
growth  develops  at  about  the  same  age  in  parent 
and  offspring,  or  in  which  a  mental  aberration 
similarly  manifests  itself. 

Such  manifestations  of  heredity  are  spoken  of 
[273] 


LUTHER  BUKBANK 

as  "homochronous,"  but  the  big  word  scarcely 
adds  anything  to  the  observed  facts. 

The  same  may  be  said  of  the  words  "homotic" 
and  "heterotopic"  heredity,  sometimes  employed 
to  express  the  fact  that  an  inherited  anomaly — 
say  a  tumor — may  appear  in  the  same  tissues  of 
the  body  of  parent  and  offspring  (homotic),  or  in 
another  case  in  different  tissues  (heterotopic). 

The  fact  is,  as  regards  this  particular  matter, 
that  a  tendency  to  the  development  of  a  tumor 
may  be  inherited,  but  that  the  precise  location  of 
the  tumor  may  perhaps  be  determined  by  the  ex- 
traneous circumstances — say  a  local  irritation. 

The  inheritance  of  special  abnormalities  of  a 
precise  and  definite  character — say  a  lock  of  white 
hair  located  on  a  particular  part  of  the  head,  as 
a  typical  example — is  likely  to  arouse  surprise 
and  to  call  forth  comment  on  the  mysteries  of  in- 
heritance; yet  rightly  considered  such  a  phenom- 
enon is  no  more  remarkable  than  the  inheritance 
of  all  the  ordinary  characteristics  that  lead  to 
what  is  familiarly  spoken  of  as  a  family  resem- 
blance. 

No  one  is  surprised  that  the  eyes  or  hair  or 
complexion  or  stature  or  shape  of  nose  or  habits 
of  mind  in  any  individual  strikingly  resemble  the 
same  qualities  of  the  individual's  father. 

In  other  words,  the  broad  general  facts  of 
heredity  are  accepted  as  matters  of  fact  without 
seeming  to  call  for  special  comment.  Stated 
otherwise,  this  is  no  more  than  saying  that  no  one 
is  surprised  that  grapes  grow  on  grape  vines  and 

[274] 


THE  LAWS  OF  HEREDITY 

figs  on  fig  trees.  We  would  be  astounded  were 
the  conditions  reversed;  and  this  evidences  the 
almost  axiomatic  character  of  the  great  funda- 
mental law  of  heredity,  and  its  universal  accept- 
ance as  a  part  of  common  knowledge. 

MINGLING   MODIFIED   GEKM-PLASMS 

In  all  this,  then,  we  are  expositing  the  idea 
that  the  racial  germ-plasm  conveys  the  record  of 
past  environments  and  predetermines  the  char- 
acteristics and  qualities  of  the  organism  that  may 
grow  from  that  germ-plasm.  As  thus  far  viewed, 
therefore,  the  facts  connoted  in  the  familiar 
phrase  "like  parent,  like  child "  are  scarcely 
more  mysterious  than  the  fact  that  successive 
cups  of  water  dipped  from  the  same  stream 
should  be  like  one  another. 

But  there  is  a  vastly  complicating  fact  which 
we  have  thus  far  purposely  ignored — the  familiar 
fact,  namely,  that  each  higher  organism  is  not  the 
offshoot  of  a  single  parent,  but  a  product  of  the 
union  of  two  parents. 

Be  it  plant  or  animal,  every  individual  above 
the  very  lowest  strata  of  organic-like  owes  its 
being  to  the  union  of  two  germ-cells.  It  represents 
the  commingling  of  two  strains  of  racial  germ- 
plasm.  Pollen  grain  unites  with  ovule  in  the  case 
of  the  plant;  sperm-cell  with  ovule  in  the  case  of 
the  higher  animal;  and  each  type  of  cell  conveys 
its  own  coterie  of  hereditary  potentialities. 

This  is  the  essential  and  primary  fact  that  com- 

[275] 


LUTHER  BURBANK 

plicates  the  entire  situation.  The  fact  of  double 
parentage  is  one  that  will  be  seen  at  a  glance  to 
remove  all  simplicity  from  the  formula  "like  pro- 
duces like."  For  no  two  individuals  are  precisely 
alike;  no  two  cells  of  the  germ-plasm  carry  pre- 
cisely the  same  ancestral  traits. 

The  briefest  consideration  will  suggest  some,  at 
least,  of  the  complications  that  necessarily  result 
when  more  or  less  divergent  germ-plasms  are 
commingled. 

Of  course,  if  two  ancestral  germ-plasms  are 
too  widely  divergent  they  cannot  commingle  at  all. 
The  two  organisms  are  then  said  to  be  mutually 
infertile.  This  was  formerly  supposed  to  be  the 
case  with  most  different  species.  Indeed,  the  test 
of  capacity  to  interbreed  with  the  production  of 
fertile  offspring  was  long  considered  to  be  the 
best  test  of  specific  identity.  Nowadays  we  know, 
thanks  largely  to  Mr.  Burbank's  experiments, 
that  this  test  cannot  be  fully  relied  upon.  Never- 
theless, it  is  clear  that  only  species  that  are  some- 
what closely  related  can  interbreed. 

Even  where  union  takes  place  between  mem- 
bers of  the  same  species,  however,  there  are  sure 
to  be  some  divergent  traits  that  are  more  or  less 
in  conflict.  It  may  chance  even  that  there  are 
numerous  minor  traits  that  are  mutually  antago- 
nistic. 

For  example,  to  take  the  simplest  and  most 
familiar  case,  animals  of  the  same  species  may 
differ  radically  in  color.  One  guinea-pig  may  be 
jet  black  and  another  pure  white.  It  is  obvious, 

[276] 


THE  LAWS  OF  HEREDITY 

in  such  a  case,  that  the  offspring  cannot  be  like 
both  parents  in  color. 

Here,  then,  is  a  complication  that  introduces 
an  element  of  uncertainty  into  the  otherwise  sim- 
ple law  of  heredity. 

It  is  perhaps  not  too  much  to  say  that  all  ques- 
tions of  heredity  center  chiefly  around  the  in- 
quiry as  to  just  what  are  the  mutual  relations  of 
more  or  less  antagonistic  qualities  when  com- 
mingled through  cross-fertilization. 

HYBRIDIZATION  AND  VARIATION 

At  an  early  stage  of  his  work  in  plant  develop- 
ment, Mr.  Burbank  discovered  that  it  is  possi- 
ble to  hybridize  species  that  are  seemingly  quite 
divergent,  and  that  the  results  are  often  very 
striking.  He  brought  together  plants  from  differ- 
ent continents,  and  found  that  in  many  cases  they 
would  interbreed. 

For  example,  he  hybridized  the  Siberian  rasp- 
berry with  the  California  dewberry,  producing  a 
remarkable  new  fruit  which  he  called  the  Primus 
berry. 

Everyone  is  familiar  with  the  conspicuous 
differences  between  a  raspberry  and  a  blackberry. 
To  mention  only  one  of  them,  the  raspberry  leaves 
its  receptacle  on  the  vine  when  picked,  while  the 
blackberry  retains  the  receptacle  as  part  of  the 
fruit.  It  at  once  becomes  an  interesting  question 
as  to  how  these  divergent  qualities  are  harmon- 
ized in  hybridized  offspring. 

[277] 


LUTHER  BURBANK 

In  point  of  fact,  inspection  of  the  hybrid 
Primus  berry  shows  that  each  parent  strove  to 
transmit  its  own  peculiarity  as  regards  this  mat- 
ter of  the  receptacle.  The  result  is  that  the  Pri- 
mus berry,  if  plucked  just  at  the  moment  when  it 
is  approaching  maturity,  acts  like  a  blackberry, 
bringing  away  the  receptacle  as  part  of  the  fruit. 
But  if  the  fruit  is  left  on  the  vine  until  a  little 
past  the  moment  of  maturity,  it  shows  the  prop- 
erty of  the  raspberry,  leaving  the  receptacle  on 
the  vine,  and  coming  away  as  a  cup-shaped  fruit. 
Here,  then,  there  is  a  compromise  in  which  it 
may  be  said  that  each  line  of  ancestral  tendencies 
makes  its  influence  felt. 

In  general,  it  may  be  said  that  this  case  is 
typical.  As  a  rule,  the  different  traits  of  plants 
or  animals  that  can  be  interbred  are  not  so  widely 
divergent  as  to  be  absolutely  antagonistic,  and 
the  offspring  is  likely  to  show  a  blending  of  the 
traits.  There  are  numerous  cases,  however,  in 
which  a  compromise  is  not  so  readily  effected, 
and  in  which  one  trait  or  the  other  seems  for  the 
moment  to  be  predominant. 

As  an  illustration  of  this,  take  the  case  of  Mr. 
Burbank's  white  blackberry.  If  this  is  crossed 
with  a  black  blackberry,  the  hybrid  bush  will  bear 
only  black  berries;  the  tendency  of  the  white 
blackberry  to  reproduce  itself  seems  entirely  sub- 
ordinated. 

But,  although  for  the  moment  subordinated, 
the  tendency  to  produce  white  berries  is  not  lost 
from  the  germ-plasm  of  the  hybrid.  The  proof 

[278] 


THE  LAWS  OF  HEREDITY 

of  this  is  found  in  the  fact  that  in  the  next  gener- 
ation a  certain  proportion  of  the  progeny  will 
bear  white  berries.  This  reappearance  of  a  sub- 
merged trait  in  the  second  and  in  subsequent 
generations  furnishes  one  of  the  most  striking 
and  interesting  aspects  of  the  entire  subject  of 
heredity. 

THE  PKODUCTION  OF  MUTANTS 

Mr.  Burbank  had  not  proceeded  far  in  his 
studies  of  hybridization  before  he  discovered  that 
the  most  astonishing  segregation  and  redistribu- 
tion of  characters  may  take  place  in  second- 
generation  hybrids. 

If  he  crossed  two  parent  strains  that  were  more 
or  less  divergent,  he  might  find  the  traits  of  the 
parents  variously  blended  in  the  hybrids  of  the 
first  generation ;  but  if  he  interbred  these  hybrids, 
he  was  almost  sure  to  get  in  the  next  generation 
a  conglomerate  fraternity,  showing  the  traits  of 
the  grandparental  forms  reasserted  into  almost 
every  imaginable  combination.  More  than  that, 
there  were  likely  to  appear  forms  that  diverged 
markedly  from  either  of  the  grandparents. 

It  would  seem  that  the  mingling  of  divergent 
germ-plasms  had  made  possible  the  rejuvenescence 
of  ancestral  traits  that  had  long  been  submerged. 

Mr.  Burbank  found  that  by  carefully  inbreed- 
ing individuals  that  showed  the  new  or  revived 
trait  he  could  accentuate  the  quality  and  in  many 
cases  produce  new  varieties  so  markedly  different 

[279] 


LUTHER  BURBANK 

from  either  of  the  grandparental  forms  as  to  jus- 
tify his  use  of  the  term  "new  creations. " 

The  only  plausible  explanation  of  such  anom- 
alies is  that  the  qualities  thus  newly  revealed  and 
accentuated  were  traits  that  had  been  manifested 
by  remote  ancestors,  but  which  had  been  subordi- 
nated and  submerged  through  conflict  with  other 
more  or  less  antagonistic  traits  in  the  ancestral 
germ-plasm. 

So  striking  were  the  modifications  that  Mr. 
Burbank  was  thus  enabled  to  produce  at  will 
through  the  hybridizing  of  divergent  forms  that 
he  came  to  feel  confident  of  being  able  to  modify 
almost  any  form  of  plant  life,  and  produce  strik- 
ing new  varieties,  provided  an  allied  form  could 
be  found  with  which  hybridization  could  be  ef- 
fected. 

When  the  celebrated  Amsterdam  botanist,  Pro- 
fessor Hugo  De  Vries,  came  forward  with  his 
theory  of  mutation,  according  to  which  a  form  of 
plant  life  may  now  and  again  diverge  radically 
from  its  parent  forms  through  "spontaneous" 
variation,  constituting  a  new  form  of  "mutation," 
Mr.  Burbank  was  first  to  assert  that  such  mutant 
forms  were  explicable  as  due  to  hybridization. 

He  asserted  that  he  himself  produced  muta- 
tions at  will  through  hybridization,  and  the  long 
list  of  his  plant  developments  afforded  striking 
verification  of  his  claim. 

More  than  this,  Mr.  Burbank 's  experiments 
led  him  to  believe  that  hybridization  takes  place 
among  plants  and  animals  in  a  state  of  nature 

[280] 


DWARF  CHESTNUT  TREE. 

This  reproduction  of  a  direct  color-photograph  shows  a  bush-like 
tree  that  is  a  fine  example  of  a  Burbank  hybrid  chestnut.  The 
workman  who  stands  beside  the  tree  is  five  feet  seven  inches  tall. 
Note  the  abundant  crop  of  nuts  on  the  tree  and  under  the  tree. 
Gathering  chestnuts  becomes  a  simple  matter  when  the  trees  are  of 
this  type. 


THE  LAWS  OF  HEREDITY 

much  more  commonly  than  had  hitherto  been 
supposed,  and  that  such  hybridization  is  often 
responsible  for  the  production  of  new  forms  that 
may  play  an  important  part  in  the  scheme  of  evo- 
lution. He  believes,  indeed,  that  hybridization 
largely  accounts  for  the  origin  of  those  variations 
which  Darwin  had  been  content  to  speak  of  as 
"spontaneous,"  and  which  are  recognized  as  the 
material  with  which  natural  selection  works  in 
developing  new  species. 

MENDELIAN    HEREDITY 

The  striking  results  in  the  production  of  new 
varieties  through  hybridization  that  Mr.  Burbank 
had  attained  became  known  to  horticulturists 
and  biologists,  and  probably  had  an  important 
share  in  preparing  the  world  to  look  with  interest 
on  the  experiments  of  the  Austro-Silesian  monk, 
Mendel,  when  the  obscure  report  that  this  ex- 
perimenter had  published  as  long  ago  as  1863 
was  rediscovered  just  at  the  close  of  the  nine- 
teenth century. 

Mendel,  working  chiefly  with  the  garden  pea, 
had  paid  attention  (as  we  have  already  seen)  to 
a  few  conspicuous  characters  regarding  which 
different  races  of  garden  peas  differ. 

He  had  observed  the  mutual  relations  in  the 
inheritance  of  such  qualities  as  tallness  versus 
shortness  of  vine,  pinkness  versus  whiteness  of 
flower,  yellowness  versus  greenness  of  pod,  etc., 
and  had  traced  very  definitely  and  with  scientific 

[281] 


LUTHER  BURBANK 

precision  the  relations  of  these  qualities  in  cross- 
bred plants  of  the  first  and  second  generations. 
In  so  doing  he  reduced  to  a  definite  formula  the 
observation  of  the  mingling  of  traits  in  the  first 
generation  and  their  redistribution  and  recombi- 
nation in  the  second,  which  Mr.  Burbank  has  ob- 
served to  be  so  common  a  phenomenon  with  the 
great  number  of  species  with  which  he  worked. 

But  Mendel  went  further.  He  formulated  a 
theory  as  to  the  causes  that  operate  to  determine 
the  relations  of  antagonistic  characteristics  when 
brought  together  through  the  mingling  of  diver- 
gent germ-plasms ;  and  his  theory  was  at  once  so 
simple  and  so  satisfactory  that  it  has  now  come  to 
be  accepted  at  least  as  a  provisional  hypothesis 
everywhere. 

According  to  this  theory,  every  tangible  char- 
acteristic of  any  organism  is  determined  by  the 
mingling  in  the  embryonic  germ-plasm  of  two 
hereditary  "factors"  or  "determiners,"  the  jux- 
taposition of  which  is  essential  to  the  production 
of  the  character  in  question.  If  these  factors 
represent  the  same  quality,  there  will,  of  course, 
be  no  antagonism,  and  the  quality  of  the  resulting 
character  will  not  be  in  doubt.  But  if,  on  the 
other  hand,  the  two  factors  are  antagonistic — 
one,  let  us  say,  representing  a  black  berry  and  the 
other  a  white  berry — the  result  may  be  that  one 
factor  entirely  dominates  the  other,  the  subordi- 
nated character  seeming  to  have  no  representation 
whatever. 

But  the  factor  thus  submerged  reproduces  it- 
[  282  ] 


THE  LAWS  OF  HEREDITY 

self  and  distributes  its  representatives  in  the 
germ-cells  of  the  next  generation  quite  as  freely 
as  does  the  dominant  factor.  So  there  is  an  even 
chance  that  factors  of  the  subordinate  type  will 
be  represented  in  the  germ-cells  that  are  to  pro- 
duce progeny  of  a  second  generation. 

According  to  the  mere  theory  of  chances,  if  we 
mix  together  indiscriminately  a  quantity  of  black 
factors  and  white  factors  in  equal  numbers,  and 
pick  out  pairs  of  factors  at  random,  it  must  result 
that  in  any  average  group  of  four  pairs  we  shall 
find  one  pair  of  black  factors,  one  pair  of  white 
factors,  and  two  pairs  of  mixed  factors. 

If  you  will  experiment  with  checker-men,  draw- 
ing them  in  pairs  from  a  mixed  lot,  you  will  be 
surprised  to  find  how  generally  you  approximate 
the  formula,  even  when  small  numbers  are  in 
question. 

NATURE'S  GAME  OF  CHANCE 

According  to  Mendel's  interpretation,  nature 
performs  such  an  experiment  whenever  two  germ- 
cells  bearing  antagonistic  factors  have  come  to- 
gether, and  the  results  of  her  game  of  chance  are 
seen  in  the  phenomena  of  what  have  come  to  be 
spoken  of  as  Mendelian  heredity. 

Tangibly  illustrated,  the  result  is  that  when, 
for  instance,  a  pea  having  a  tall  vine  is  crossed 
with  one  having  a  short  vine,  the  offspring  will  be 
tall;  but  their  offspring  will  be  represented,  on 
the  average,  by  one  tall  vine  (pure  dominant) 
that  will  breed  absolutely  true,  one  short  vine 

[283] 


LUTHER  BURBANK 

(pure  recessive)  that  will  also  breed  absolutely 
true,  and  two  tall  vines  (mixed)  that  will  not 
breed  true  because  they  contain  factors  both  of 
tallness  and  of  shortness. 

The  essential  truth  of  the  Mendelian  formula 
has  been  demonstrated  by  thousands  of  observa- 
tions, but  a  good  many  workers  who  have  ob- 
served its  application  in  simple  cases  have  failed 
to  realize  the  true  bearing  of  the  phenomena.  The 
truth  seems  to  be  that  it  is  only  the  comparatively 
superficial  and  newly  acquired  characteristics  of 
any  organism  that  still  have  sufficient  flexibility 
to  be  experimented  with  by  nature  in  this  game 
of  chance  that  we  speak  of  as  Mendelian  heredity. 

Stated  otherwise,  what  we  term  Mendelian 
inheritance  appears  to  be  nature's  method  of  test- 
ing out  new  qualities  that  are  from  time  to  time 
impressed  on  the  organism  through  the  influence 
of  environment. 

Some  individuals  of  a  certain  strain  of  plants 
or  animals  chance  to  be  subjected  to  influences 
that  modify  somewhat  the  color  of  flowers,  the 
texture  of  hair,  the  size  of  body,  or  what  not.  An 
individual  of  this  modified  race  presently  inter- 
breeds with  an  individual  not  so  modified. 

The  important  question  is  this:  Is  the  modi- 
fication beneficial  to  the  species  or  otherwise? 

The  matter  is  put  to  an  impartial  test  through 
the  operation  of  Mendelian  heredity. 

All  the  immediate  offspring  present  tangibly 
the  modified  character,  but  the  unmodified  char- 
acter is  given  a  hearing  again  the  next  genera- 

[284] 


THE  LAWS  OF  HEREDITY 

tion.  And  if  the  modification  is  neither  favorable 
nor  unfavorable  to  the  race,  it  may  chance  that 
two  varieties,  one  showing  the  modification  and 
the  other  without  it,  will  continue  to  flourish  in 
the  same  environment. 

As  a  typical  instance — taken  at  random — you 
may  find  gray  screech-owls  and  red  ones  in  the 
same  brood. 

If,  however,  the  modification  is  favorable,  the 
individuals  possessing  it  will  ultimately  prevail 
over  those  lacking  it,  and  it  will  be  added  to  the 
regular  equipment  of  the  species.  If,  contrari- 
wise, the  unmodified  character  was  better  adapted 
to  meet  the  requirements  of  environment,  it  will 
prevail,  and  the  individuals  having  the  modifica- 
tion will  be  weeded  out. 

A  pure  "recessive,"  as  we  have  seen,  carries 
no  factors  for  the  antagonistic  "dominant"  qual- 
ity. Thus  it  may  come  about  that  certain  traits 
of  a  given  organism  are  absolutely  eliminated 
from  the  germ-plasm  of  a  fixed  proportion  of  the 
descendants  of  that  organism.  Thus — anomalous 
though  it  seem — an  individual  may  be  of  "pure" 
strain  notwithstanding  the  fact  that  one  of  his 
grandparents  was  of  different  strain;  and  the 
known  laws  of  heredity  pretty  clearly  explain  the 
anomaly. 

This  is  the  one  really  new  conception  in  the 
present-day  interpretation  of  the  laws  of  heredity. 
The  older  idea  was  that  any  trait  once  impressed 
on  the  organism  remains  forever  as  a  latent  char- 
acter in  the  germ-plasm,  and  is  susceptible  of 

[285] 


LUTHER  BURBANK 

being  made  tangible  in  some  of  the  progeny 
under  favorable  conditions. 

The  laws  of  Mendelian  inheritance  show  us 
that  the  factors  of  heredity  may  be  so  redis- 
tributed that  individuals  of  the  same  parentage, 
and  hence  precisely  the  same  heredity,  broadly 
speaking,  are  radically  different  in  their  innate 
hereditary  tendencies  as  regards  some  minor  but 
perhaps  not  inconsequential  qualities. 

The  new  knowledge  does  not  controvert  the 
old  rule  that  "like  produces  like,"  but  it  gives  us 
new  insight  into  the  interpretation  of  that  rule. 
In  its  practical  bearing  on  the  interpretation  of 
heredity  as  applied  to  human  beings,  the  new 
knowledge  takes  precedence  in  importance  over 
all  that  has  hitherto  been  known  about  heredity. 

Until  the  Mendelian  interpretation  was  avail- 
able, no  one  could  pretend  to  fathom  the  mysteries 
of  atavism,  much  less  to  predict  as  to  the  prob- 
able recurrence  of  submerged  ancestral  qualities 
in  any  given  generation. 

But  the  Mendelian  formula  serves  as  a  work- 
ing hypothesis  that  enables  us  in  many  cases  to 
predict  with  a  fair  degree  of  certainty  what  will 
be  the  result  of  the  union  of  individuals  of  known 
heredity. 

Thanks  to  this  hypothesis,  however,  the  laws  of 
heredity  in  their  application  to  the  human  organ- 
ism now  take  on  a  definiteness  that  they  hitherto 
have  lacked. 


[286] 


THE  LAWS  OF  HEREDITY 

MENDELISM    AND    INSANITY 

As  an  illustration  in  point,  let  us  note  the  re- 
sults of  some  recent  studies  which  give  us  new 
light  on  the  heritability  of  that  most  pitiable  of 
human  afflictions,  insanity. 

It  seems  to  be  established  that  the  forms  of 
nervous  instability  that  lay  the  foundation  for 
insanity  tend  to  act  as  Mendelian  recessives  in 
heredity. 

It  follows  that  if  an  insane  person  is  mated 
with  a  perfectly  normal  one,  the  offspring  will 
probably  be  personally  normal,  although  carrying 
the  factors  of  nervous  instability  in  their  germ- 
plasm.  But  if  two  individuals  having  this  heri- 
tage are  mated,  even  though  both  are  personally 
normal,  there  will  almost  certainly  be  evidence  of 
nervous  instability  in  at  least  one  in  four  of  their 
offspring. 

Consideration  of  the  Mendelian  formula,  which 
has  been  fully  stated  in  earlier  chapters  of  this 
book,  makes  it  clear  why  the  examination  of 
pedigrees,  to  determine  whether  heredity  enters 
into  the  causation  of  any  given  case  of  insanity, 
must  be  extended  beyond  the  first  generation  of 
the  ancestry,  and  in  collateral  lines. 

It  will  be  recalled  that  a  recessive  trait  makes 
itself  tangibly  manifest  only  when  the  factors  for 
recessiveness  are  combined  in  the  germ-plasm, 
uncomplicated  by  the  presence  of  the  opposite 
factors ;  and  hence  that  the  recessive  traits  always 
" breed  true."  This  explains  the  observation  of 

[287] 


LUTHER  BURBANK 

psychiatrists  who  report  that,  in  cases  under  ob- 
servation, where  two  persons  both  of  whom  are 
insane  are  mated  their  offspring  all  become  in- 
sane. 

It  is  obvious,  then,  that  the  question  of  selec- 
tion of  marriage  partners  for  persons  in  whose 
families  there  is  a  strain  of  insanity  is  a  highly 
important  one.  Mendelian  heredity  explains  how 
it  is  possible  that,  in  a  fraternity  whose  parents 
were  "  mixed  dominants "  as  regards  the  factors 
for  mental  instability,  one  individual  may  inherit 
a  perfectly  sound  and  normal  nervous  system, 
whereas  an  own  brother  or  sister  of  this  individ- 
ual— even  a  twin — may  inherit  a  nervous  system 
so  unstable  as  to  invite  overthrow. 

This  must  be  borne  in  mind  whenever  we  con- 
sider the  question  of  persons  in  whose  families 
there  are  strains  of  insanity. 

Unfortunately  a  recessive  trait,  in  the  case  of  a 
mixed  dominant,  may  be  so  completely  submerged 
that  it  gives  no  manifestation  whatever  of  its 
presence.  Yet  it  will  come  to  the  surface  no  less 
surely  if  this  person  marries  with  another  mixed 
dominant.  So  the  only  safe  rule  in  a  case  where 
there  is  known  to  be  insanity  in  the  family  heri- 
tage is  to  avoid  marrying  into  another  family 
having  a  like  defect. 

It  is  obvious  that  cousin  marriages  under  these 
circumstances  would  be  peculiarly  hazardous. 


[288] 


THE  LAWS  OF  HEREDITY 

BREEDING   FOE   GENIUS 

There  is,  however,  another  aspect  of  the  sub- 
ject of  cousin  marriages  that  must  not  be  over- 
looked in  the  present  connection.  It  is  true  that 
such  unions  involve  the  danger  of  accentuating 
strains  of  nervous  instability  in  the  family 
through  combination ;  but  it  is  also  true  that  there 
is  the  possibility  of  accentuating  nervous  and 
mental  characteristics  that  underlie  genius  itself. 

In  point  of  fact,  the  old  tradition  about  the 
affinity  between  genius  and  insanity  is  not  alto- 
gether without  foundation.  Men  of  the  very 
highest  type  of  genius,  to  be  sure,  are  eminently 
sane;  yet  it  would  appear  that  there  are  certain 
attributes  of  sensitiveness  of  nervous  organiza- 
tion, tendency  to  egoism,  and  almost  preter- 
natural energy  that  may  occur  from  time  to  time 
in  a  family  and  may  in  some  instances  be  com- 
bined in  such  a  way  as  to  produce  genius,  while 
in  other  instances  they  induce  insanity. 

To  advocate  the  marriage  of  cousins  in  a  fam- 
ily characterized  by  exceptional  qualities  of  brain 
would,  therefore,  be  in  a  sense  hazardous,  yet  it 
might  result  directly  in  the  production  of  men 
of  genius. 

A  very  good  illustration  of  the  possibility  of 
producing  a  fraternity  of  exceptional  individuals 
through  the  union  of  cousins  who  are  themselves 
exceptional  is  furnished  by  the  pedigree  of  Fred- 
erick the  Great.  In  point  of  fact,  this  pedigree 
furnishes  a  striking  illustration  of  close  inbreed- 

[289] 


LUTHER  BURBANK 

ing  not  unlike  that  which  Mr.  Burbank  practices 
when  he  would  accentuate  a  desirable  quality  in 
one  of  his  plant  families.  The  case  has  double 
interest  in  the  present  view  because,  in  consider- 
ing it,  we  are  brought  back  to  the  family  of  the 
seven  brothers  whose  practical  experiment  in 
eugenic  breeding  was  referred  to  in  an  earlier 
chapter. 

It  will  be  recalled  that  of  the  seven  brothers 
only  one  married,  and  that  in  the  succeeding  gen- 
erations the  duty  of  transmitting  the  family  name 
devolved  upon  one  Ernest  Augustus,  Bishop  of 
Osnabriick,  who  married  an  extraordinary 
woman,  Sophia  of  Palatine.  The  child  of  this 
union  was  married  to  a  daughter  of  the  Bishop's 
brother,  and  these  cousins  were  the  grandparents 
of  Frederick  the  Great  and  his  distinguished  fra- 
ternity. 

When  a  chart  showing  the  full  genealogy  of 
this  extraordinary  family  is  shown  it  appears  that 
the  father  and  mother  of  Frederick  the  Great 
were  cousins ;  that  both  pairs  of  his  grandparents 
in  turn  were  cousins ;  and  that  his  paternal  grand- 
mother was  the  sister  of  his  maternal  grandfather 
and  cousin  of  his  maternal  grandmother. 

In  the  third  generation,  of  four  pairs  of  an- 
cestors, one  pair  appears  in  both  paternal  and 
maternal  strains,  so  that  there  are  only  six  per- 
sons, and  two  of  the  six  are  brothers;  there  be- 
ing only  five  ancestral  strains  of  blood  repre- 
sented, instead  of  the  normal  eight. 

Here,  then,  is  an  extraordinary  case  of  inbreed- 
[290] 


THE  LAWS  OF  HEREDITY 

ing,  in  which  are  combined  the  strains  of  many 
remarkable  individuals;  for  in  addition  to  those 
already  mentioned  the  pedigree  shows,  in  the 
third  generation,  two  other  remarkable  women, 
Eleanor  d'Olbreuze  and  Louisa  Henrietta  of 
Orange,  the  latter  a  descendant  of  the  Great  Wil- 
liam the  Silent  and  the  only  less  celebrated  Gas- 
pard  the  Second. 

The  blood  of  William  the  Silent  appears  in 
three  other  strains  of  the  pedigree,  and  that  of 
Mary  Queen  of  Scots  in  two  strains. 

In  a  word,  there  is  scarcely  an  undistin- 
guished male  among  the  forty  individuals  who 
represent  Frederick's  ancestors  within  five  gen- 
erations ;  the  fact  that  these  are  but  forty,  instead 
of  the  normal  sixty-two  individuals,  in  itself  re- 
veals graphically  the  extent  to  which  the  vari- 
ous strains  of  this  distinguished  ancestry  are 
interwoven  through  an  intricate  web  of  inbreed- 
ing. 

The  progeny  of  this  extraordinary  experiment 
in  eugenics  reveal,  in  the  generation  upon  which 
our  attention  is  focused,  not  only  Frederick  II, 
one  of  that  small  select  company  of  all  time  who 
by  common  consent  are  surnamed  "the  Great/' 
but  a  brother  Henry  and  a  sister  Amelia  almost 
equally  gifted,  and  a  sister,  Sophia  Ulrica,  who 
may  be  said  to  stand  fully  on  a  par  in  intel- 
lectual endowment  with  her  illustrious  brother, 
and  who  as  Queen  of  Sweden  was  known  as  i '  the 
Minerva  of  the  North,"  and  became  the  mother 
of  the  famous  Gustavus  III. 

[291] 


LUTHER  BURBANK 

INBEEEDING  FOE  DEGENEEACY 

But  lest  too  sweeping  a  conclusion  be  drawn 
from  this  remarkable  example  of  inbreeding  for 
genius,  it  is  desirable  that  we  should  at  once  turn 
to  another  royal  pedigree  and  observe  the  effects 
of  inbreeding  where  the  traits  combined  and  ac- 
centuated are  not  preponderantly  desirable  ones, 
as  in  the  case  of  Frederick  the  Great,  but  include 
also  elements  of  mental  aberration  and  physical 
and  mental  degeneracy. 

Such  a  pedigree  is  supplied  in  the  immediate 
ancestry  of  Don  Carlos,  the  "  madly  depraved  and 
cruel"  scion  of  the  Spanish  royal  house,  a  man 
who  has  been  characterized  as  the  most  heartless 
and  depraved  individual  in  modern  history. 

A  glance  at  a  chart  showing  the  ancestry  of 
Don  Carlos  reveals  that  his  father,  Philip  II,  and 
his  mother,  Mary  of  Portugal,  were  at  once  first 
and  second  cousins,  and  that  each  ancestral  strain 
leads  quickly  back  to  ancestors  characterized  as 
weak  or  cruel  or  mad. 

Joana  "the  mad"  appears  twice  in  the  third 
generation,  and  the  insane  Isabella  four  times  in 
the  fifth  generation. 

The  inbreeding  is  so  close  and  intricate  that 
it  would  be  difficult  to  characterize  the  relation- 
ship. In  five  generations  there  are  only  twenty- 
eight  individuals  instead  of  the  normal  sixty-two. 
Thus  a  profoundly  neurotic  strain  is  allowed  to 
become  overwhelmingly  preponderant  by  repeti- 
tion. As  Dr.  F.  A.  Woods  has  said,  it  was  as  if 

[292] 


THE  LAWS  OF  HEREDITY 

the  sovereigns  of  that  time  were  breeding  mental 
monstrosities  for  a  bench  show.  Their  experi- 
ment shows  the  eugenic  principle  inverted. 

But  the  feature  of  the  pedigree  of  the  de- 
praved Don  Carlos  which  chiefly  concerns  us  at 
the  moment  is  the  fact  that  there  appear  in  the 
table,  mingled  with  the  names  of  the  weaklings, 
the  mentally  unbalanced,  and  the  morally  de- 
praved, the  names  of  several  famous  characters, 
including  Charles  the  Bold  of  Burgundy,  Maxi- 
milian I  of  the  Holy  Roman  Empire,  Ferdinand 
and  Isabella  the  Catholics,  and  the  Emperor 
Charles  V.  What  further  excites  surprise  is  that 
the  names  of  Ferdinand  and  Isabella  appear  again 
and  again  in  the  fourth  generation,  and  that  in 
the  heritage  of  Isabella  there  seems  to  be  an  al- 
ternation of  generations  between  insanity  and 
genius. 

This  gives  practical  illustration  of  the  affinity 
— above  referred  to — between  mental  aberration 
and  genius  of  a  certain  type.  It  suggests  further 
that  genius  and  mental  impairment  follow  the 
same  law  of  inheritance. 

There  is  a  growing  body  of  evidence  to  show 
that  both  views  are  valid.  In  recent  years  investi- 
gation has  been  made  not  only  on  the  bad  strains 
of  royal  pedigree,  but  on  the  heredity  of  genius 
and  of  insanity  among  people  in  general,  and  the 
result  is  that  we  are  nearer  an  understanding  of 
this  hitherto  obscure  subject  than  ever  before. 

The  puzzling  thing  has  always  been  that  the 
children  of  the  man  or  woman  of  genius  very 

[293] 


LUTHER  BURBANK 

commonly  have  no  genius;  yet  that  they  some- 
times seem  able  to  transmit  genius  to  their 
descendants. 

No  explanation  of  this  anomaly  was  forthcom- 
ing until  the  recent  studies  gave  a  clew  through 
the  suggestion  that  genius  is  a  unit  character  (or 
group  of  traits)  which  acts  in  inheritance  as  a 
negative  or  so-called  "  recessive "  character. 

It  is  pretty  obvious,  then,  that  we  cannot  al- 
ways tell  just  what  will  be  the  result  when  repre- 
sentatives of  families  having  neurotic  strains  in- 
termarry. There  may  be  cases  in  which  it  will 
be  difficult  to  predict  as  to  whether  the  children 
will  probably  be  stable  geniuses  or  persons  of  very 
unstable  nervous  system.  But  as  the  former  are 
very  rare  or  the  latter  very  common,  it  follows 
that  the  chance  of  favorable  results  from  a  union 
that  thus  blends  neurotic  strains  is  far  from 
favorable. 


[294] 


CHAPTER  XIII 
NURTURE  VERSUS  NATURE 

REPORTS  have  recently  come  from  New 
Zealand  that  tell  a  remarkable  story 
about  the  Monterey  pine.  This  tree  is 
indigenous  to  California.  It  grows  in  very  re- 
stricted regions,  and  the  comparatively  few 
individual  trees  that  are  now  in  existence  are 
supposed  to  be  reminiscent  of  a  remote  prehis- 
toric flora.  Indeed,  the  chief  interest  of  the  tree 
hitherto  has  been  the  fact  that  it  is  found  in  so 
restricted  an  area,  and  in  such  small  numbers. 

But  now  word  comes  from  New  Zealand  that 
this  tree  has  proved  to  have  very  remarkable 
qualities  when  grown  in  that  country.  Someone 
made  the  experiment  of  transporting  the  Monte- 
rey pine  to  New  Zealand  a  good  many  years  ago, 
and  this  change  of  environment  appears  to  have 
had  a  most  extraordinary  effect. 

Whereas  the  Monterey  pine  in  its  native  coun- 
try is  practically  valueless  from  an  economic 
standpoint,  it  proves  so  remarkable  a  producer  of 
wood  in  its  new  home  that  it  has  there  received 
the  name  "The  Wonderful  Tree." 

Reports  tell  us  that  the  Monterey  pine  in  this 
new  habitat  exceeds  all  other  trees  in  rapidity  of 

[295] 


LUTHER  BURBANK 

growth,  and  produces  an  amount  of  valuable 
lumber  that  is  quite  without  precedent. 

No  species  of  pine  in  America  produces  lum- 
ber at  a  rate  at  all  comparable  to  the  records 
that  come  to  us  from  New  Zealand,  telling  of  the 
extraordinary  productivity  of  the  Monterey  pine, 
which  in  its  native  climate  is  of  such  slow  growth 
and  produces  timber  of  such  poor  quality  that  it 
is  not  usually  listed  among  timber-producing  trees 
of  economic  value. 

Now  it  is  obvious  that  the  transplantation  of 
the  Monterey  pine  from  California  to  New  Zea- 
land can  in  no  wise  have  affected  the  hereditary 
tendencies  of  the  tree.  Whatever  capacities  for 
growth  and  timber  production  are  revealed  by  the 
tree  in  New  Zealand  must  have  existed  as  poten- 
tial qualities  in  the  seed  that  was  taken  to  New 
Zealand  from  California.  The  change  has  not 
been  brought  about  from  hybridization  or  by 
selective  breeding. 

It  is  merely  that  a  new  environment — new  soil, 
different  climate — has  taken  a  hand  in  the  de- 
velopment of  the  submerged  hereditary  factors; 
and  under  these  new  influences  the  tree  has  been 
made  to  reveal  possibilities  that  were  hitherto  un- 
suspected. 

So  the  case  of  the  Monterey  pine  affords  a  very 
striking  demonstration  of  the  influence  of  en- 
vironment in  bringing  out  unsuspected  hereditary 
tendencies.  It  furnishes  an  object  lesson  in  the 
power  of  nurture  to  supplement — and  even,  on 

[296] 


HYBRID  MASSACHUSETTS  ELM  OX  CAL 


ROOTS 


Note  the  different  quality  of  bark  at  the  base  of  the  tree,  representing 
the  California  stock,  on  which  the  twig  brought  from  Massachusetts  was 
grafted.  The  tree  is  only  fifteen  years  old,  and  its  extraordinarily  rapid 
growth  is  ascribed  by  Mr.  Burbank  to  the  fact  that  the  parent  from 
which  the  twig  was  cut  was  a  natural  hybrid. 


NURTURE  VERSUS  NATURE 

occasion,  seemingly  to  supplant — the  power  of 
nature. 

AN  IMMIGEANT  BHUBARB 

But  this  very  striking  demonstration  of  the 
modifications  in  the  life  history  of  an  organism 
that  may  be  brought  about  through  changed  en- 
vironment is  by  no  means  without  precedent. 

Something  quite  comparable  has  been  ob- 
served, for  example,  when  the  migration  has  been 
effected  in  the  opposite  direction,  the  plant  being 
brought  from  the  southern  hemisphere  to  our  own 
northern  latitudes. 

The  case  of  the  eucalyptus  tree,  which  takes 
on  extraordinary  capacities  of  growth  in  Califor- 
nia, is  perhaps  not  to  be  too  greatly  emphasized 
because  this  tree  is  also  a  rapid  grower  in  its 
native  Australian  soil.  But  there  are  other  plants 
that  seem  to  reveal  new  possibilities,  in  particular 
when  brought  to  California  from  the  southern 
hemisphere. 

As  a  typical  instance,  we  may  recall  Mr.  Bur- 
bank's  winter  rhubarb.  This  plant,  when  Mr. 
Burbank  first  imported  it  from  Australia,  had  a 
stalk  scarcely  larger  than  a  lead  pencil.  The  sole 
value  of  the  plant  from  an  economic  standpoint, 
and  the  thing  that  gave  it  chief  interest  for  Mr. 
Burbank,  was  the  fact  that  it  had  the  habit  of  put- 
ting forth  stalks  in  cold  weather. 

Lower  temperature  appeared  to  have  the  effect 
of  stimulating  it,  just  as  high  temperatures  stimu- 
late most  other  vegetables. 

[297] 


LUTHER  BURBANK 

Mr.  Burbank  saw  in  this  peculiar  habit  the  pos- 
sibility of  producing  a  valuable  market  vegetable 
that  would  mature  at  times  when  the  ordinary 
pie-plant  is  dormant.  The  expectation  was  veri- 
fied. Under  the  changed  environmental  condi- 
tions of  California,  the  winter  rhubarb  developed 
wonderfully,  without  hybridization,  until  its  stalk 
was  many  times  larger  than  the  original  plant 
from  the  antipodes.  Meantime  it  retained  its 
habit  of  putting  forth  stalks  most  abundantly  dur- 
ing the  period  of  cold  weather. 

But  of  course  the  winter  season  in  California 
corresponds  with  the  summer  in  Australia.  So  in 
putting  forth  its  stalks  in  cold  weather  at  Santa 
Rosa  the  plant  was  modifying  its  habit  radically, 
as  tested  by  the  calendar.  That  is  to  say,  it  now 
puts  forth  its  stalks  in  response  to  the  stimulus  of 
cold  weather  from  November  to  January,  instead 
of  from  June  to  August. 

Here,  then,  was  a  case  in  which  changed  con- 
ditions of  the  environment,  as  marked  by  the 
most  radical  shift  of  seasons,  sufficed  to  transpose 
the  time  of  bearing  of  the  plant,  twisting  it  an  en- 
tire half-year  out  of  reckoning. 

But  meantime  the  hereditary  clockwork  mech- 
anism within  the  cells  of  the  plant,  through  which 
its  time  of  development  had  been  adjusted  for  the 
months  of  June,  July,  and  August,  still  main- 
tained its  force;  so  the  plant,  thanks  to  this  in- 
herent impulse — and  now  operating  in  defiance  of 
environing  conditions — continued  to  put  forth  its 
stalks  abundantly  at  its  accustomed  time,  which 

[298] 


NURTURE  VERSUS  NATURE 

now,  under  the  changed  conditions,  coincides  with 
the  summer  season. 

The  net  result  of  these  two  sets  of  impulses 
was  that  the  plant  continued  to  be  a  "winter  rhu- 
barb, ' '  yet  was  now  a  '  '  summer  rhubarb ' '  as  well. 

And  by  selecting  for  a  few  generations  among 
the  plants  that  showed  greatest  tendency  to  pro- 
long the  seasons,  Mr.  Burbank  was  able  to  merge 
winter  bearing  and  summer  bearing,  bridging  the 
gaps  of  spring  and  autumn,  until  his  perfected 
plant,  while  he  still  designated  it  as  a  "winter 
rhubarb/ '  was  in  reality  practically  an  all-the- 
year  bearer. 

Meanwhile,  by  further  selection,  aided  now  by 
hybridization,  it  was  found  possible,  thanks 
largely  to  the  aid  of  the  new  environment,  to 
stimulate  the  plant  to  such  unwonted  vigor  of 
growth  that  the  descendant  of  a  plant  which  came 
to  California  with  a  pencil-sized  stalk  now  pro- 
duced a  stalk  comparable  rather  to  a  broom- 
handle,  lifting  its  leaves  several  feet  into  the  air, 
and  fully  meriting  the  name  of  Giant  Winter 
Rhubarb. 

ENVIRONMENT  VEKSUS   HEEEDITY 

Here  again,  obviously,  we  are  given  a  striking 
illustration  of  the  power  of  environment  to  bring 
out  concealed  hereditary  potentialities.  We  dare 
not  suggest  that  environment  has  introduced  new 
traits  that  did  not  exist  in  the  hereditary  mechan- 
ism of  the  plant.  To  suggest  this  would  be  to  im- 

[299] 


LUTHER  BURBANK 

ply  that  environment  may  transform  an  organism 
in  a  single  generation  in  a  way  so  radical  as  to 
bid  defiance  to  specific  bounds;  making  the  se- 
quence of  evolution  a  haphazard  performance 
which  we  cannot  believe  compatible  with  the  or- 
derly progress  of  nature. 

We  are  bound  to  believe,  then,  that  when  we 
see  a  plant  transformed  as  to  its  tangible  proper- 
ties in  a  single  generation,  or  in  a  few  generations, 
through  the  influence  of  changed  environment, 
we  are  witnessing  the  bringing  out  of  suppressed 
tendencies,  the  realization  of  submerged  poten- 
tialities, rather  than  the  implantation  and  de- 
velopment of  really  new  traits. 

Making  the  interpretation  specific,  we  must 
believe  that  the  Monterey  pine,  which  now  in 
California  is  a  tree  of  stunted  growth,  had  an- 
cestors that  were  rapid-growing  mammoth  trees. 
Through  unfavorable  conditions — the  result,  per- 
haps, of  a  glacial  epoch — the  tree  gradually  modi- 
fied its  habits  of  growth  and  perhaps  preserved 
its  life  through  such  modification ;  but  the  heredi- 
tary factors  for  gigantic  growth  still  existed  in 
its  germ-plasm,  and  awaited  only  a  favorable 
opportunity  to  make  themselves  again  manifest. 
The  opportunity  came  when  some  chance  seeds  of 
the  tree  were  transported  to  New  Zealand,  where 
it  chanced  that  the  conditions  of  soil  and  climate 
were  such  as  to  favor  these  long-submerged 
hereditary  factors,  giving  them  opportunity  to 
prove  their  existence  and  their  latent  potentiali- 
ties for  development. 

[300] 


NURTURE  VERSUS  NATURE 

Similarly  the  small  winter  rhubarb,  with  its 
pencil-like  stalks,  as  Mr.  Burbank  found  it  in  Aus- 
tralia, must  be  regarded  as  the  dwarfed  descend- 
ant of  some  tropical  plant  of  the  elder  day  which 
had  been  forced  to  modify  its  manner  of  growth 
to  meet  altered  conditions  of  climate,  but  which 
retained  in  its  germ-plasm,  even  as  the  Monterey 
pine  retained,  the  factors  for  relatively  gigantic 
growth,  biding  their  time  and  ready  to  make  re- 
sponse to  altered  conditions  of  nurture. 

Their  opportunity  came  when  seeds  of  the  plant 
were  brought  from  the  antipodes  to  California, 
just  as  the  opportunity  of  the  submerged  factors 
of  the  Monterey- pine  was  found  when  the  migra- 
tion was  made  in  the  opposite  direction. 

AN  EXAMPLE  FEOM  THE  ANIMAL  WOELD 

Were  anyone  disposed  to  doubt  the  validity  of 
this  interpretation,  to  question  whether  environ- 
ment has  in  reality  such  wonderful  capacity  to 
alter  the  seeming  mandates  of  heredity,  evidence 
in  substantiation  may  be  found  in  quite  different 
fields. 

Take,  for  example,  the  very  familiar  case  of  the 
worker  bee.  This  insect,  as  is  well  known,  is  an 
immature  and  sterile  female.  Under  normal  con- 
ditions in  the  hive,  there  are  thousands  of  eggs, 
each  like  all  the  others,  and  each  destined  to  de- 
velop into  a  sterile  worker. 

But  on  occasion  the  mature  workers  in  the  hive 
enlarge  the  cell  in  which  one  of  these  worker  eggs 

[301] 


LUTHER  BURBANK 

is  deposited,  and  feed  the  larva  which  hatches 
from  it  with  an  unusual  quantity  of  food  of  excep- 
tional richness.  And  the  individual  larva  thus 
singled  out  for  exceptional  nurture  grows  and 
develops  at  a  rate  disproportionate  to  that  of  its 
fellows,  and  ultimately  matures  and  becomes  a 
fertile  female,  which,  in  the  terminology  of  the 
apiary,  is  designated  a  queen. 

This  mature  individual  presently  goes  forth 
from  the  hive  with  a  band  of  followers,  and  es- 
tablishes a  new  colony.  She  in  turn  deposits  eggs 
and  becomes  the  mother  of  another  swarm  of 
drones  and  workers. 

Yet  nothing  is  more  certain  than  that  the  hered- 
itary potentialities  of  the  egg  which  thus  was 
transformed  into  a  queen  bee  were  in  no  wise 
different  from  the  potentialities  of  the  thousands 
of  other  eggs  about  it  that  developed  only  into 
sterile  workers.  Nurture  alone  determined  the 
transformation.  In  this  case  it  was  purely  a 
matter  of  food.  There  was  no  climatic  change 
invoked  or  needed.  Feeding  alone  sufficed  to 
bring  about  a  final  development  of  the  reproduc- 
tive organs  that  was  denied  all  the  other  larvae 
of  the  colony. 

This  case  of  the  bee  is  so  familiar  that  its  won- 
derful significance  is  often  overlooked. 

Taken  by  itself,  it  suffices  to  illustrate  the  over- 
mastering power  of  nurture  to  decide  among  the 
conflicting  hereditary  tendencies  that  lie  dormant 
in  the  germ-cell. 

Lest  the  case  seem  to  prove  too  much,  however, 
[302] 


NURTURE  VERSUS  NATURE 

let  us  not  forget  that  it  is  only  the  eggs  of  the 
worker  that  through  such  treatment  can  be  de- 
veloped into  queens.  There  are  also  in  the  normal 
hive  other  eggs,  produced  parthenogenetically, 
which  will  develop  into  male  or  drone  bees,  and 
which  can  by  no  possibilities  of  altered  nutrition 
be  transformed  into  workers  or  queens,  any  more 
than  the  worker  eggs  could  be  made  to  develop 
into  drones. 

But  this  illustration,  after  all,  serves  only  to 
give  recognition  to  the  fundamental  fact  that 
heredity,  in  the  last  analysis,  puts  certain  definite 
limitations  on  environmental  interference. 

No  conceivable  environing  conditions  can  be 
expected,  in  the  nature  of  the  case,  to  bring  out 
potentialities  that  do  not  exist.  A  dwarfed  Mon- 
terey pine  may  be  transformed  through  altered 
nurture  into  a  mammoth  pine ;  a  dwarfed  rhubarb 
into  a  giant  rhubarb ;  a  worker  bee  into  a  queen 
bee.  But  no  conceivable  modification  of  nurture 
could  transform  the  Monterey  pine  into  a  rhubarb 
of  any  sort,  or  the  rhubarb  into  a  pine,  or  either 
pine  or  rhubarb  into  a  bee. 

To  suggest  such  transformation  would  be 
grotesque.  Yet  these  extreme  cases  are  perhaps 
worth  citing  to  emphasize  the  fact  that  when  we 
speak  of  the  power  of  nurture  over  nature — as 
applied  to  any  given  individual — we  refer  only  to 
a  power  of  selection  between  divergent  hereditary 
tendencies. 

The  pine  has  become  a  pine  through  endless 
generations  of  development;  the  rhubarb  has  be- 

[303] 


LUTHER  BURBANK 

come  a  rhubarb,  and  the  bee  has  become  a  bee, 
through  the  same  slow  process  of  evolution. 

Each  of  these  organisms,  and  every  other  spe- 
cific organism  of  all  the  myriads,  has  its  own  con- 
geries of  hereditary  factors,  and  by  no  conceiv- 
able influence  can  these  be  suddenly  transformed. 

What  has  been  developed  through  the  slow 
process  of  the  ages  can  be  modified  through  a 
similar  slow  process  of  future  ages.  Yet  within 
each  organism,  by  virtue  of  the  slow  development 
and  modification  through  the  past  ages,  there  are 
stored  up  multitudes  of  hereditary  factors  that 
are  more  or  less  in  antagonism,  only  one  or  an- 
other series  of  which  can  be  made  manifest  in  a 
given  generation.  And  the  power  of  environ- 
ment is  exercised  in  selecting  between  or  among 
these  conflicting  factors. 

Nurture  could  not  determine  that  the  Monte- 
rey pine  should  cease  to  be  a  pine,  but  it  could  de- 
termine whether  it  should  be  a  dwarf  or  a  giant. 
Nurture  could  transform  a  worker  into  a  queen, 
but  not  into  a  drone. 

The  illustrations  from  the  vegetable  and  ani- 
mal worlds  have  been  used  to  make  the  case 
tangible.  Let  us  now  turn  attention  to  the  human 
organism,  and  study  the  application  of  this  prin- 
ciple to  the  development  of  the  human  child. 

THE  PEINCIPLES  OP  EUGENICS 

When  the  word  "eugenics"  first  came  before 
the  public  a  few  years  ago,  there  were  strong  ob- 

[304] 


A  FINE  SPECIMEN  OF  THE  ROYAL  WALNUT 

This  new  Bin-bank  variety  was  produced  by  crossing  the  Eastern  and 
Western  black  walnuts.  It  grows  to  exti-aordinary  size  in  a  relatively  short 
period.  The  specimen  here  shown  is  only  fifteen  years  old. 


NURTURE  VERSUS  NATURE 

jections  to  its  supposed  implications,  on  senti- 
mental grounds. 

Much  of  the  opposition  has  died  away  in  re- 
cent years,  showing  a  very  remarkable  modifica- 
tion of  public  sentiment.  But  even  now  it  is  not 
unusual  to  hear  the  feasibility  of  any  attempted 
application  of  eugenic  principles  challenged,  on 
the  ground  that  nature,  having  been  in  the  busi- 
ness of  matchmaking  from  time  immemorial,  is 
very  well  able  to  carry  on  this  business  without 
interference  from  the  scientific  students  of 
heredity. 

Such  objections  are  reminiscent  of  the  thought 
of  an  elder  day,  when  the  current  phrase  about 
marriage  being  made  in  heaven  was  taken  more 
than  half  seriously,  and  when  the  entire  attitude 
of  mind  of  the  public  toward  the  question  of  the 
relations  of  the  sexes  was  far  more  puritanical 
than  it  is  at  present. 

Many  causes  have  conspired  to  change  public 
sentiment;  and  the  very  fact  that  the  name 
"eugenics"  has  made  its  way  so  rapidly  proves 
that  the  intelligent  moiety  of  the  public  has  be- 
come prepared  to  give  recognition  to  the  idea  that 
man  may  conceivably  exercise  a  directive  influ- 
ence in  the  breeding  of  his  own  race  such  as  he  has 
all  along  exercised  in  the  breeding  of  the  animals 
that  he  has  domesticated. 

The  argument  that  nature  herself  is  the  ideal 
matchmaker  is  seen  on  the  slightest  critical  in- 
spection to  be  utterly  fallacious;  in  particular 
since  it  has  come  to  be  known  that  hundreds  of 

[305] 


LUTHER  BURBANK 

thousands  of  children  are  born  into  the  world 
foredoomed  to  disease  or  to  defective  mentality 
by  the  mismating  of  their  parents. 

In  the  older  conception,  heredity  was  fatalistic. 
So  long  as  it  was  believed  that  all  the  character- 
istics of  a  parent  are  transmitted  to  all  his  chil- 
dren, it  seemed  inevitable  that  the  sins  of  the 
parents  must  be  visited  upon  the  children,  in  strict 
accordance  with  the  biblical  mandate.  But  the 
new  knowledge  of  Mendelian  heredity  makes  it 
clear  that  the  hereditary  factors  in  the  germ- 
plasm  of  an  individual  may  be  potent  or  impotent 
in  their  tangible  influence  on  the  next  generation, 
according  to  the  combinations  that  are  made  with 
the  hereditary  factors  of  the  other  parent. 

We  have  seen,  for  example,  that  factors  for 
mental  deficiency  or  for  susceptibility  to  consump- 
tion, even  though  present  in  the  germ-plasm  of 
an  individual,  may  be  utterly  unable  to  make 
themselves  tangibly  manifest  if  that  individual 
mates  with  one  in  whose  germ-plasm  the  factors 
for  normal  mentality  only  and  for  resistance  to 
consumption  are  present. 

Thus  the  mandate  that  seemed  to  condemn  the 
offspring  may  in  many  cases  be  rendered  nuga- 
tory by  the  right  selection  of  marriage  partners. 

Here,  then,  is  a  specific  instance  in  which  a 
definite  knowledge  of  the  laws  of  heredity  might 
serve  to  determine  whether  the  offspring  of  an 
individual  should  be  normal  or  defective;  where, 
in  a  word,  the  principles  of  eugenics  might  be 
practically  applied  with  benefit  to  a  fraternity  of 

[306] 


NURTURE  VERSUS  NATURE 

individuals.  And  if  it  be  objected  that  such  an 
application  of  cold  scientific  principles  seems  to 
rob  marriage  of  all  romance,  it  is  perhaps  an 
adequate  and  comprehensive  answer  to  point  out, 
as  I  have  been  moved  to  do  on  various  occasions, 
that  there  is  nothing  appealingly  romantic  about 
a  brood  of  epileptic  or  neurotic  or  imbecile 
children. 

It  is  possible,  however,  to  supplement  this  sug- 
gestion with  the  assurance  that,  in  general,  the  ap- 
plication of  eugenic  principles  to  the  mating  of 
human  beings  would  not  by  any  means  necessitate 
the  supplanting  of  the  old  traditional  method  of 
matchmaking,  but  would  only  serve  as  a  supple- 
mentary procedure,  aimed  at  the  perfecting  of  a 
method  which  must  be  admitted  to  lack  something 
of  the  ideal. 

NATURE  AS  EUGENTST 

In  point  of  fact,  it  requires  but  the  most  casual 
knowledge  of  the  subject  to  convince  one  that 
nature  herself  is  the  original  eugenist,  and  that 
the  motives  that  actuate  individuals  under  the 
spell  of  the  god  of  love  are  essentially  eugenic 
motives. 

To  substantiate  this  suggestion,  it  is  only  nec- 
essary to  call  attention  to  the  fact  expressed  by 
the  common  saying  that  opposites  attract.  This 
means  that  a  person  is  drawn  toward  one  of  the 
opposite  sex  whose  predominating  tendencies  cor- 
respond to  his  subordinated  ones. 

[307] 


LUTHER  BURBANK 

Note,  as  practical  illustrations,  how  the  tall 
man  is  attracted  by  the  small  woman,  blonde  by 
brunette,  genius  by  mediocrity.  It  is  even  matter 
of  common  experience  that  the  most  virtuous 
young  women  are  often  fascinated  by  opposite 
moral  traits  in  their  male  associates;  while,  con- 
trariwise, the  most  vicious  men  would  always 
choose  virtuous  helpmates  if  they  could. 

These  propensities  have  long  been  recognized, 
and  they  have  been  explained  as  representing  a 
tendency  of  nature  to  avoid  extremes  and  keep 
near  to  a  happy  mean.  It  has  been  observed  that 
extreme  development  in  any  direction  leads  to  in- 
stability, and  -it  is  everywhere  accepted  that  a 
well-rounded  development  is,  on  the  average, 
preferable  to  a  highly  specialized  development  in 
one  direction.  But  the  real  significance  of  the 
observed  tendency  of  opposite  physiques  and 
temperaments  to  attract  each  other  is  more 
clearly  explicable  than  ever  before  since  a  knowl- 
edge of  Mendelian  heredity  has  given  clews  to  its 
true  interpretation. 

The  fact  seems  to  be  that  what  we  term  Men- 
delian heredity  represents  nature's  incessant  at- 
tempt to  improve  the  race. 

It  is  an  observed  fact  that  physical  strength 
and  vigor  are  dominant  factors;  hence  the  off- 
spring of  a  strong  individual  and  a  feeble  one  are 
likely  to  be  strong.  It  is  obviously  desirable,  then, 
from  a  eugenic  standpoint,  that  weak  individuals, 
if  they  are  to  mate  at  all,  should  mate  with  strong 
ones.  And  nature  has  all  along  provided  that  this 

[308] 


NURTURE  VERSUS  NATURE 

should  take  place,  through  establishing  the  nat- 
ural affinity  of  weak  for  strong  and  of  strong  for 
weak,  just  referred  to. 

It  is  matter  of  everyday  observation  that 
women  of  a  masculine  type  are  attracted  to  more 
or  less  effeminate  men;  and,  contrariwise,  that 
men  of  the  most  virile  type  are  drawn  to  women 
who  are  the  embodiment  of  femininity.  And  the 
most  coldly  logical  student  of  scientific  eugenics 
must  applaud  these  inherent  preferences. 

In  a  word,  then,  it  may  be  said  that  the  new 
science  of  eugenics  does  not  come  forward  as  a 
revolutionary  force,  but  only  as  a  supplementary 
force.  In  general,  the  study  of  scientific  heredity 
has  sufficed  to  show  the  logicality  of  spontaneous 
love,  rather  than  to  suggest  its  illogicality.  But 
this  verdict  must  be  modified  to  the  extent  of  urg- 
ing that  it  may  be  possible  for  the  student  of 
heredity  to  point  out  individual  instances  in  which 
a  scientific  analysis  reveals  impediments  to  what 
otherwise  might  be  a  thoroughly  eugenic  and  de- 
sirable mating. 

In  other  words,  the  province  of  eugenics  at  the 
present  stage  of  its  development  is,  as  has  been 
suggested  in  an  earlier  chapter,  not  so  much  to 
determine  whom  an  individual  should  marry  as 
to  show,  on  occasion,  whom  he  or  she  should  not 
marry.  The  definite  implications  and  applica- 
tions of  this  principle  will  appear  as  we  proceed. 
A  clew  to  them  is  given  in  the  statement  that  eu- 
genics is  recognized  as  having  two  quite  different 
aspects,  a  negative  and  a  positive  aspect. 

[309] 


LUTHER  BURBANK 

Negative  eugenics  aims  to  prevent  the  birth  of 
the  unfit;  positive  eugenics  aims  to  bring  about 
the  birth  of  the  fit. 

We  must  consider  each  of  these  subjects  inde- 
pendently, but.it  may  fairly  be  said  at  the  outset 
that  negative  eugenics  has  far  wider  present-day 
application  and  is  of  more  immediately  practical 
import  to  our  race  than  positive  eugenics. 

THE   BREEDING   OF   THE   UNFIT 

It  is  a  familiar  observation  everywhere  to-day 
that  the  better  classes  of  citizens  as  a  rule  have 
fewer  children  than  the  less  desirable  classes. 

A  striking  illustration  of  this  is  furnished  by 
some  statistics  recently  collected  by  Professor 
Cattell,  of  Columbia  University,  showing  that  the 
families  of  a  large  number  of  the  more  distin- 
guished scientific  men  in  America  consist,  on  the 
average,  of  less  than  two  members.  And  this  ob- 
servation is  fairly  in  accord  with  the  general 
observation,  according  to  which  the  members  of 
the  community  that  should  be  looked  to,  from  a 
eugenic  standpoint,  to  propagate  the  species  are 
the  ones  who  have  the  smallest  families. 

Contrariwise,  it  is  matter  of  equally  familiar 
observation  that  the  people  of  the  slums  of  our 
cities,  the  recent  immigrants  representing  the 
lower  orders  of  European  population,  and  the  de- 
fective and  criminal  classes,  are  vigorous  and 
prolific  breeders. 

This,  obviously,  amounts  to  saying  that  in- 

[310] 


NURTURE  VERSUS  NATURE 

crease  of  population  is  largely  promoted  by  the 
less  desirable,  rather  than  by  the  more  desirable, 
members  of  the  community. 

Whereas  all  evolutionary  progress  in  the  past 
has  been  due,  we  are  led  to  believe,  largely  to 
natural  selection  of  the  fittest  members  of  the 
animal  and  vegetable  populations  as  the  propa- 
gators of  the  species,  mankind  is  now  making 
the  experiment  of  artificial  selection,  in  which 
the  survival  of  the  unfit  becomes  the  outstanding 
feature. 

It  is  as  if  Mr.  Burbank  were  to  select  among 
cross-bred  plants  the  ones  that  showed  the  least 
desirable  qualities,  and  were  carefully  to  preserve 
the  seed  of  these,  destroying  the  seed  of  the  more 
desirable  members  of  the  colony.  It  needs  no 
profound  knowledge  of  plant  breeding  to  predict 
what  must  come  to  pass  were  this  plan  to  be  fol- 
lowed in  the  orchard  or  field  or  garden.  No  one 
will  for  a  moment  suppose  that  Mr.  Burbank 
could  have  produced  his  remarkable  new  varieties 
of  plants  by  such  a  method.  No  one  doubts  that 
the  application  of  such  a  method  would  result  in 
the  rapid  retrogression  of  even  the  best  varieties, 
so  that  they  would  presently  be  represented  by  a 
degenerate  progeny. 

It  is  equally  little  in  doubt  that  a  breeder  of 
thoroughbred  horses,  or  of  special  varieties  of 
dogs  or  chickens  or  pigeons,  would  work  havoc  in 
the  ranks  of  his  pedigreed  stock  were  he  to  en- 
courage the  breeding  of  inferior  members  and  re- 
strict the  breeding  of  superior  ones. 

[311] 


LUTHER  BURBANK 

No  one  doubts  that  the  same  laws  of  heredity 
apply  to  plants,  to  animals,  and  to  the  human 
race.  How,  then,  can  we  doubt  that  the  present 
customs  of  human  society,  in  which  the  less  fit 
members  of  the  community  are  by  far  the  most 
prolific,  must  tend  to  encourage  racial  degenera- 
tion? 

Seemingly  there  can  be  no  difference  of  opin- 
ion on  this  question.  But  serious  differences  arise 
when  we  proceed  to  the  natural  inquiry  as  to  what 
may  best  be  done  to  change  the  existing  condi- 
tions. 

The  statement  that  it  is  desirable  to  increase 
the  prolificness  of  the  better  classes  and  to  restrict 
the  fecundity  of  the  inferior  and  defective  classes, 
considered  as  an  abstract  proposition,  will  pass 
unchallenged. 

But  whenever  the  attempt  is  made  to  suggest 
specific  means  through  which  these  ends  may  be 
attained,  such  suggestions  are  sure  to  be  met  with 
violent  opposition. 

Nevertheless,  it  is  incumbent  upon  us,  in  the 
present  connection,  to  endeavor  to  view  the  situa- 
tion without  sentimentality,  and  from  the  stand- 
point of  the  student  of  heredity. 

In  particular,  we  are  called  upon  to  make 
application,  as  best  we  may,  of  the  principles  of 
plant  development  that  are  revealed  by  a  study  of 
Mr.  Burbank's  work,  in  their  bearing  on  the 
breeding  of  the  human  plant.  And  when  we  view 
the  matter  from  this  standpoint,  it  would  appear 
that  there  are  at  least  a  few  specific  propositions 

[312] 


•ifc^Ml/.,, 


^  a,  a 
o     ^ 

0  O)  d) 


NURTURE  VERSUS  NATURE 

that  may  be  urged  with  a  fair  measure  of  assur- 
ance. 

EESTKICTING  THE  FECUNDITY  OF  THE  UNFIT 

First  and  foremost  among  these  is  the  belief 
that  the  notoriously  unfit  members  of  the  com- 
munity, as  represented  by  criminals,  the  insane, 
and  the  mentally  defective,  should  on  no  account 
be  permitted  to  have  progeny. 

These  defectives  represent  a  recessive  element 
in  the  human  germ-plasm.  And  all  our  modern 
studies  make  it  increasingly  clear  how  difficult  it 
is  to  eliminate  a  recessive  trait  from  the  strains 
of  any  race  of  organisms.  To  be  sure,  a  recessive 
quality  disappears  altogether  in  the  first  filial 
generation  when  mingled  in  the  germ-plasm  with 
the  antagonistic  and  dominant  quality.  But  it  not 
only  reappears  tangibly  in  a  certain  proportion 
of  the  offspring  of  the  second  generation,  but  it 
also  remains  as  a  latent  factor  in  the  germ-plasm 
of  two  out  of  three  of  the  progeny  of  that  genera- 
tion who  give  no  outward  evidence  of  its  presence. 

Such,  it  will  be  recalled,  is  the  characteristic 
feature  of  Mendelian  inheritance,  and  when  we 
consider  the  facts  from  the  present  point  of  view, 
it  might  fairly  be  questioned  whether  the  terms 
dominant  and  recessive  might  not  better  have 
been  reversed.  It  is  far  easier  to  fix  a  recessive 
quality,  because  its  tangible  manifestation  proves 
the  absence  of  the  corresponding  dominant  fac- 
tors. But  we  have  no  way  of  telling  that  any  or- 

[313] 


LUTHER  BURBANK 

ganism  showing  a  dominant  quality  does  not  carry 
the  opposite  recessive  factors  dormant  in  its 
germ-plasm. 

So  far  as  we  can  judge,  there  is  no  limit  to 
the  number  of  generations  through  which  the  fac- 
tors for  a  recessive  quality  may  be  conveyed  in  a 
state  of  latency  or  impotence,  and  yet  may  become 
active  and  make  themselves  manifest  through  a 
chance  mingling  with  germ-plasm  conveying  simi- 
lar recessive  factors  in  the  same  state  of  latency. 

If  I  correctly  understand  the  matter,  recessive 
characters  are  characters  that  are  relatively  old 
in  the  evolutionary  sense,  and  dominant  char- 
acters are  those  that  are  relatively  new.  In  each 
and  every  case  where  antagonistic  qualities  are 
matched  against  each  other  there  is  reason  to 
believe  that  the  newer  character  will  tend  to  mani- 
fest the  phenomena  of  dominance,  and  the  older 
character  the  phenomena  of  recessiveness.1 

The  entire  Mendelian  formula  might  be  said 
to  express  nature's  receptiveness  toward  innova- 
tion, on  one  hand,  and  her  tendency  to  hold  fast 
to  that  which  has  been  proved  good,  on  the  other 
hand. 

An  organism  that  has  acquired  a  new  char- 

1  Perhaps  it  should  be  explained  that  this  interpretation  of  the 
underlying  nature  of  the  phenomena  of  dominance  and  recessive- 
ness  is  original  with  the  writer.  It  is  based  on  a  rather  wide 
study  of  the  phenomena  of  Mendelian  heredity  in  both  vegetable 
and  animal  worlds.  It  exactly  reverses  the  explanation  that  has 
been  suggested  by  some  other  biologists,  but  the  writer  believes 
that  it  is  the  most  plausible  interpretation  of  the  phenomena  in 
question  hitherto  suggested.  The  basis  for  this  belief  will  be  else- 
where set  forth  in  detail. 

[314] 


NURTURE  VERSUS  NATURE 

acter  mates  with  an  organism  in  which  the  same 
character  is  of  an  older  type.  The  progeny  all 
give  outward  manifestation  of  the  new  character. 
But  their  progeny  show  the  recurrence  of  the  old 
character  in  one  case  in  four,  and  two  other  mem- 
bers of  the  four  carry  the  factors  for  this  quality 
as  a  recessive  element  in  their  germ-plasm.  If 
the  new  character  is  beneficial  to  the  species,  the 
individuals  showing  it  (who  in  the  second  genera- 
tion, it  will  be  recalled,  outnumbered  their  fel- 
lows of  the  same  fraternity  three  to  one)  will 
thrive  and  propagate  their  kind,  and  the  individ- 
uals having  the  new  quality  will  increase  rapidly 
in  number. 

But  meantime  there  is  always  a  possibility  that 
the  new  character  may  be  beneficial  only  under 
local  conditions  or  for  a  limited  period ;  so  nature 
is  by  no  means  minded  to  renounce  the  old  char- 
acter all  at  once.  Generation  after  generation, 
she  provides  that  the  factors  for  the  recessive 
traits  shall  be  carried  forward,  and  that  a  certain 
proportion  of  the  individuals  of  each  generation 
shall  be  " mixed  dominants,"  whose  offspring  will 
have  representatives  showing  the  old  character. 
So  even  when  the  new  character  is  a  highly  bene- 
ficial one,  the  old  character  still  tends  to  recur  and 
to  fight  for  recognition. 

But  if,  on  the  other  hand,  the  new  character  is 
one  that  is  not  beneficial,  the  individuals  that 
show  it  are  quickly  weeded  out,  and  only  the  re- 
cessive members  of  the  fraternity  remain.  In 
other  words,  a  new  or  dominant  character  must  be 

[315] 


LUTHER  BURBANK 

advantageous  to  its  possessor — or  at  all  events 
not  detrimental — or  it  is  quickly  eliminated,  be- 
cause there  is  no  such  thing  as  the  carrying  for- 
ward of  this  character  as  a  latent  element  in  the 
germ-plasm.  But  the  old  and  therefore  recessive 
character  may  be  carried  forward  in  the  germ- 
plasm  generation  after  generation,  for  the  very 
reason  that  it  is  not  outwardly  manifested,  and 
therefore  does  not  handicap  the  individual  in 
whose  germ-plasm  it  rests. 

Now  we  have  seen  that  certain  notable  defects 
of  the  human  organism,  which  are  manifested  in 
mental  deficiency  or  insanity,  act  as  recessive 
traits  in  inheritance.  The  same  thing  is  true  of 
the  allied  defects  that  are  the  foundation  of  crimi- 
nality. We  are  led  to  infer,  then,  that  these  con- 
ditions of  mental  and  moral  obliquity  represent 
earlier  stages  of  human  evolution.  The  individ- 
uals who  manifest  these  defects  in  any  given  gen- 
eration are  those  whose  ancestors  have  mated  in 
such  an  unfortunate  way  as  to  preserve  the  re- 
cessive character  either  as  a  patent  or  a  latent 
factor  in  their  germ-plasm.  In  effect,  the  men- 
tally and  morally  deficient  classes  of  to-day  be- 
long to  a  remote  generation  of  the  past.  The 
hereditary  factors  that  are  responsible  for  their 
mental  equipment  have  come  down  unchanged 
from  remote  ancestors  who  lived  under  conditions 
of  barbarism  in  which  the  traits  that  we  now  de- 
scribe as  aberrant  or  defective  were  a  part  of  the 
normal  equipment  of  the  race. 

In  the  long  stretch  of  intervening  generations, 
[316] 


NURTURE  VERSUS  NATURE 

new  traits  have  been  developed  and  old  traits 
modified,  but  these  traits,  which  represent  the 
higher  attributes  of  our  mental  and  moral  na- 
tures, while  they  have  proved  dominant  to  the 
older  barbaric  traits,  have  not  been  able  to  elimi- 
nate the  old  traits  altogether  from  the  germ-plasm 
of  the  race.  So  now  and  again  there  appears  an 
individual  in  which  the  recessive  traits  are  patent ; 
and  it  merely  evidences  the  force  of  the  laws  of 
Mendelian  heredity  with  which  we  have  become 
familiar  to  note  that  these  recessive  individuals 
breed  true  to  their  recessive  quality  of  mental  and 
moral  deficiency. 

Theoretically,  we  should  expect  that  when  two 
of  these  recessives  are  mated,  their  offspring 
would  be  recessives. 

And  the  observations  of  the  alienists  and  crim- 
inologists  in  recent  years  prove  the  correctness 
of  the  preconception.  When  two  mental  defec- 
tives are  mated,  their  offspring  are  all  defectives. 
Of  course  we  can  momentarily  submerge  the  de- 
fective strain  by  mating  the  recessive  individual 
with  a  normal  individual.  But  the  progeny  all 
carry,  submerged  in  their  germ-plasm,  the  re- 
cessive factors.  Even  though  themselves  out- 
wardly normal,  they  represent  tainted  stock,  and 
the  taint  will  make  itself  manifest  sooner  or  later 
in  their  progeny.1 

1  The  question  may  arise  as  why  genius  may  also  act  as  a 
recessive  trait,  as  previously  pointed  out.  The  answer  is  that 
the  type  of  genius  that  may  so  operate  in  heredity  is  the  unstable 
of  ill-balanced  type  allied  to  insanity,  and  owing  its  success  largely 

[317] 


LUTHER  BURBANK 

Logically,  then,  there  would  seem  to  be  no 
reason  why  such  tainting  of  a  stock  should  be 
knowingly  permitted.  There  would  seem  to  be 
no  reason  why  a  recessive  individual  of  this  type 
should  be  permitted  to  vitiate  the  germ-plasm  of 
the  race.  So  long  as  the  recessive  quality  is 
latent,  we  can  do  nothing  directly  to  eliminate  it ; 
but  when  it  becomes  patent  in  an  individual  case, 
opportunity  is  afforded  to  dam  back  permanently 
that  particular  stream  of  recessive  germ-plasm. 

And  the  way  in  which  this  can  be  effected, 
obviously,  is  by  sterilization  of  the  individual  who 
manifests  the  defect. 

Still  holding  to  the  biological  point  of  view, 
there  would  seem  to  be  no  question  that  a  proper 
regard  for  the  welfare  of  future  generations  de- 
mands that  all  mentally  and  morally  defective  in- 
dividuals of  unequivocal  type  should  be  sterilized. 
The  rule  should  apply,  it  would  seem,  to  all  sub- 
normal children ;  to  the  insane  of  every  type ;  and 
to  all  persons  whose  lack  of  moral  control  is  such 
as  to  have  led  them  to  commit  infractions  of  the 
social  order  that  rank  as  felonies. 

So  comprehensive  a  programme  for  the  elimi- 
nation of  recessive  germinal  factors  for  mental 
and  moral  traits  will  doubtless  seem  little  less 
than  appalling  to  many  readers.  But  there  seems 

to  the  presence  of  an  elemental  egoism  and  excessive  energy  that 
are  primordial  traits.  Stable  genius  probably  tends  to  be  dominant 
in  heredity.  The  offspring  of  men  of  large  and  stable  mental  en- 
dowment are  usually  able.  The  sons  of  Charles  Darwin  may  be 
cited  in  illustration. 

[318] 


NURTURE  VERSUS  NATURE 

no  escape  from  the  conclusion  that  such  a  restric- 
tive programme  would  be  of  enormous  benefit  to 
the  coming  generations.  The  lessons  of  heredity 
are  futile  unless  we  are  prepared  to  act  upon 
them.  And  there  is  no  reason  why  action  should 
stop  with  halfway  measures  in  regard  to  the 
classes  just  named.  The  imbecile,  the  insane  per- 
son, and  the  criminal  are  undesirable  progenitors 
of  members  of  a  civilized  community.  In  the  in- 
terests of  the  community  they  should  be  scien- 
tifically restrained  from  incurring  the  obligations 
of  parenthood. 

That,  seemingly,  is  the  first  and  perhaps  the 
most  unequivocal  lesson  in  negative  eugenics 
that  may  be  drawn  from  the  modern  studies  of 
heredity. 

THE  QUESTION  OF  RESTRICTING  MARRIAGES 

When  we  turn  to  the  other  aspect  of  the  sub- 
ject that  has  been  most  widely  exploited — the 
question,  namely,  of  putting  legal  restrictions  on 
the  marriage  of  persons  suffering  from  various 
diseases — we  find  ourselves  on  much  more  debat- 
able ground. 

Some  rather  plausible  laws  have  been  put  on 
the  statute  books  of  various  states  in  the  past  two 
or  three  years,  making  it  obligatory  for  persons 
seeking  a  marriage  license  to  show  a  medical 
certificate  giving  them  a  clean  bill  of  health  with 
regard  to  one  or  two  transmissible  diseases.  The 

[319] 


LUTHER  BURBANK 

purpose  of  such  laws  is  obviously  commendable, 
but  it  may  seriously  be  doubted  whether  public 
opinion  has  yet  been  educated  to  the  point  where 
it  will  give  the  laws  adequate  support.  We  have 
advanced  a  long  way  in  recent  years,  but  there  is 
still  a  large  measure  of  reticence  regarding  the 
discussion  of  topics  directly  involved  in  measures 
of  this  character.  The  futility  of  attempting  to 
prevent  the  union  of  young  persons  who  have 
decided  to  marry  is  matter  of  common  knowledge. 

Moreover,  a  really  comprehensive  law  that  pre- 
vented the  marriage  of  all  incompetents  would 
fail  of  its  ultimate  object,  in  that  it  would  mainly 
result  in  substituting  illegitimate  children  for 
legitimate  ones. 

As  regards  the  commendable  attempt  to  restrict 
the  dissemination  of  venereal  diseases,  which 
is  the  essential  motive  of  the  laws  just  cited,  it 
seems  probable  that  this  end  would  be  more  ad- 
vantageously effected  by  comprehensive  sanitary 
laws  placing  all  venereal  diseases  on  a  par  with 
other  contagious  maladies;  requiring  all  cases  of 
such  diseases  to  be  reported  to  the  health  boards, 
and  inflicting  severe  penalties  on  all  persons  who 
knowingly  transmit  these  diseases. 

Such  a  sanitary  code  would  obviously  be  diffi- 
cult of  carrying  out,  but  the  great  strides  that 
public  hygiene  has  made  in  recent  years  warrant 
the  hope  that  such  measures  as  those  just  sug- 
gested will  before  long  be  thought  worthy  of  trial 
everywhere.  It  seems  more  logical  to  endeavor 
to  stamp  out  these  virulently  contagious  and 

[320] 


NURTURE  VERSUS  NATURE 

heritable  maladies  at  their  source  than  merely  to 
attempt  to  guard  a  single  avenue  among  many 
through  which  they  may  be  transmitted. 

Nevertheless,  the  placing  on  the  statute  books 
of  several  states  of  laws  of  the  character  just 
noted  may  be  taken  as  marking  a  very  notable 
stage  in  the  progress  of  the  eugenic  propaganda. 

POSITIVE  EUGENICS 

All  the  measures  thus  far  suggested  obviously 
look  to  the  restriction  of  the  breeding  of  the  unfit, 
arid  leave  quite  untouched  the  converse  side  of 
the  problem — namely,  the  stimulation  of  the  re- 
productive activities  of  the  fit.  But  we  have  al- 
ready called  attention  to  the  familiar  fact  that 
there  is  a  great  dearth  of  children  among  pre- 
cisely the  classes  who  are  best  adapted,  through 
heredity  and  through  the  environment  that  their 
homes  supply,  to  furnish  desirable  citizens  of  the 
next  generation. 

It  is  obvious,  however,  that  any  attempt  to 
regulate  the  size  of  the  families  of  the  better 
classes  of  society  lies  far  beyond  the  bounds  of 
present-day  legislation.  The  time  may  come  when 
special  bonuses  will  be  offered  in  the  way  of  ex- 
emption from  taxation  or  direct  government  sub- 
sidy for  large  families.  Such  an  expedient  is  not 
without  historical  precedent.  But  it  may  safely 
be  predicted  that  if  it  should  ever  seem  necessary 
to  resort  to  so  extreme  a  measure  in  any  civilized 
community  of  the  future,  the  provision  will  not 

[321] 


LUTHER  BUKBANK 

be  indiscriminate  in  its  application,  but  will  apply 
to  a  restricted  portion  of  the  community,  the 
favored  couples  being  such  as  adequately  meet 
conditions  imposed  by  a  eugenic  board  having  a 
fuller  knowledge  of  heredity,  perhaps,  than  any- 
one at  present  possesses. 

Materials  for  such  enhanced  knowledge  are 
being  gathered,  however,  by  the  Eugenics  Record 
Office  at  Cold  Spring  Harbor,  and  it  is  within  the 
possibilities  that  enough  family  genealogies,  col- 
lated from  a  new  point  of  view,  will  be  available 
in  the  course  of  another  decade  or  two  to  give  data 
for  a  new  type  of  pedigreed-stock  book,  of  which 
human  beings  will  be  the  subjects. 

Such  a  suggestion  probably  seems  grotesque 
to  the  average  reader ;  even  to  the  reader  who  has 
gained  a  certain  inkling  of  the  laws  of  heredity. 
Yet  a  serious  consideration  of  the  facts  as  to  the 
increase  of  population  in  recent  decades,  coupled 
with  reflections  on  the  character  of  the  increase, 
justifies  the  prediction  that  legislative  measures 
based  on  such  knowledge  will  furnish  the  basis  for 
marriage  customs  that  will  become  a  matter  of 
everyday  routine  in  the  not  very  distant  future. 

We  hear  much  clamor  about  race  suicide;  and 
when  a  nation  like  France  fails  to  increase  in 
population  as  rapidly  as  its  neighbors,  the  wise- 
acres shake  their  heads  and  talk  about  national 
degeneracy.  Yet  it  is  known  that  the  population 
of  Christendom  has  doubled  in  the  past  half -cen- 
tury, and  it  is  a  matter  of  the  simplest  computa- 
tion to  show  that  if  this  rate  of  increase  were  to 

[322] 


NURTURE  VERSUS  NATURE 

continue  there  would  not  be  standing  room  in  the 
world  for  the  human  population  in  the  year  4000 
A.D.  If  the  population  of  the  United  States  were 
to  increase  as  rapidly  in  the  coming  century  as  it 
has  in  the  past  century,  starvation  would  stare  the 
main  body  of  our  great-grandchildren  in  the  face. 

In  a  word,  the  great  menace  of  the  moment  is 
not  race  suicide  but  race  repletion. 

And,  as  we  have  seen,  it  is  the  less  desirable 
members  of  the  race  who  are  most  prolific.  Hence 
the  human  garden  is  in  danger  of  being  choked 
with  human  weeds.  There  is  eminent  need  of 
cultivation  akin  to  that  which  Mr.  Burbank  prac- 
tices when  he  would  improve  a  race  of  plants 
instead  of  allowing  them  to  run  wild  and 
deteriorate. 

Yet,  as  I  said  before,  it  must  be  admitted  that 
at  the  present  stage  of  social  development  no 
very  definite  remedies,  on  the  side  of  positive  eu- 
genics, can  be  suggested  as  capable  of  immediate 
application.  The  most  that  can  be  hoped,  per- 
haps, is  that  knowledge  of  the  laws  of  heredity 
may  be  spread  broadcast,  until  the  average  in- 
telligent citizen  is  sufficiently  informed  to  have 
logical  opinions  on  this  most  important  topic. 
When  the  time  comes  that  a  larger  number  of 
cultivated  men  and  women  have  as  comprehensive 
a  knowledge  of  heredity  as  is  now  possessed  by  a 
small  number  of  breeders  of  plants  and  special 
types  of  domesticated  animals,  and  when  the 
public  at  large  realizes  that  the  same  laws  of 
heredity  apply  to  man  as  to  all  his  fellow-beings, 

[323] 


LUTHER  BURBANK 

we  shall  be  prepared  to  consider  the  possibility  of 
measures  looking  to  the  betterment  of  the  human 
breed  through  conscious  direction  of  a  character 
not  very  different  from  that  which  has  resulted 
in  the  development  of  specialized  races  of  horses 
and  cattle  and  others  of  man's  confreres. 

Incidentally,  we  may  add  that  it  is  largely  with 
the  thought  of  aiding  in  the  promulgation  of 
knowledge  that  must  underlie  such  an  advance 
that  the  present  chapters  are  included  in  this 
book. 

THE  PBOVINCE  OP  EUTHENTCS 

In  the  meantime,  it  fortunately  chances  that  the 
obverse  side  of  the  question  of  breeding  a  better 
race  can  be  considered  with  far  less  infringement 
on  the  prejudices  of  mankind  in  general;  partly 
because  the  questions  involved  are  not  at  first 
thought  recognized  as  having  eugenic  significance. 
Eeference  is  made,  of  course,  to  the  active  move- 
ments of  recent  years  in  the  way  of  bettering  the 
environment  of  the  individuals  and  the  communi- 
ties of  our  generation.  The  work  that  has  already 
been  accomplished  in  this  regard  is  little  less  than 
revolutionary.  Its  effects  must  be  strikingly 
manifest  on  the  coming  generations. 

It  is  unnecessary  here  to  refer,  except  in  the 
most  general  way,  to  the  sanitary  reforms  in 
question.  Everyone  knows  something  of  the  en- 
heartening  story  of  how  light  is  being  let  into  the 
dark  tenement  dwellings  of  our  cities;  how  sani- 
tary guard  is  now  kept  over  the  food  supplies,  in- 

[324] 


NURTURE  VERSUS  NATURE 

eluding  in  particular  the  all-essential  milk  supply; 
how  preventive  medicine  has  learned  to  guard 
our  ports  against  the  invasion  of  plagues  and  to 
minimize  the  spread  of  the  contagious  maladies 
by  warring  upon  the  mosquitoes  and  flies  and  rats 
that  serve  as  germ-carriers. 

It  is  familiar  knowledge,  also,  that  medical 
science  has  found  means  to  treat  individuals  suf- 
fering from  contagious  maladies,  and  in  particu- 
lar to  give  immunity  to  others  through  serum 
and  vaccine  treatments,  the  discovery  of  which 
has  resulted  from  the  new  knowledge  of  bac- 
teriology. 

All  in  all,  the  work  of  preventive  medicine  has 
been  so  effectively  carried  forward  that  the  death 
rate  in  our  cities  has  decreased,  particularly  as  it 
concerns  the  infant  population,  to  a  fraction  of 
what  it  was.  The  average  age  of  mankind  has 
been  practically  doubled  since  the  time  of  our 
grandparents. 

All  this  is  matter  for  just  pride  and  enthusiasm 
to  the  humanitarian.  Yet  from  the  standpoint  of 
the  eugenist,  it  appears  that  these  triumphs  of 
preventive  medicine  do  not  represent  an  alto- 
gether unmixed  blessing.  Looked  at  with  a  coldly 
analytical  eye,  it  appears  that  the  preservation 
of  weakly  infants  through  what  may  be  likened 
to  a  hothouse  cultivation  must  enhance  the  num- 
ber of  adult  members  of  the  population  of  the 
coming  decades  who  are  peculiarly  unfit  to  propa- 
gate the  species. 

In  other  words,  it  would  appear  that  the  first 
[325] 


LUTHER  BURBANK 

notable  result  of  the  recent  betterment  in  the 
practice  of  euthenics  must  be  to  complicate  the 
problem  of  the  eugenist. 

From  the  present  standpoint,  we  could  hardly 
fail  to  recall  that  the  work  of  the  modern  hygien- 
ist  is  directly  in  opposition  to  the  method  that  Mr. 
Burbank  has  so  persistently  practiced  at  Santa 
Rosa  in  dealing  with  the  weakly  and  susceptible 
members  of  his  plant  colonies. 

From  the  outset,  the  theory  on  which  he  has 
worked,  and  worked  to  such  advantage,  has  been 
that  the  best  protection  to  his  plant  charges 
against  the  disease  with  which  they  are  menaced 
must  come  from  within  the  constitution  of  the 
plants  themselves.  So  he  has  sought  to  develop 
immune  races.  He  has  not  been  sedulous  to  find 
remedies  for  plant  diseases,  and  he  has  almost 
totally  avoided  the  use  of  sprays  and  medicants 
to  kill  off  the  fungous  and  bacterial  enemies.  His 
habit  has  been  to  check  disease  by  weeding  out 
and  destroying  the  seedlings  that  showed  sus- 
ceptibility to  disease. 

The  hardy  individuals  that  remain  owe  their 
preservation  to  the  fact  that  their  tissues  were 
able  to  fight  off  the  inimical  germs ;  and  it  was  ob- 
served that  such  immunity  is  a  heritable  trait,  so 
that  the  individuals  possessing  it  become  the 
parents  of  an  immune  race. 

It  might  seem,  then,  that  the  method  of  the 
modern  hygienist  is  a  direct  contravention  of  the 
method  which  the  plant  developer  has  found  ad- 
vantageous. A  strict  application  of  Mr.  Bur- 

[326] 


NURTURE  VERSUS  NATURE 

bank's  method  to  the  human  plant  would  suggest 
that  we  lessen  rather  than  increase  the  safe- 
guards against  bacterial  foes  that  surround  the 
average  child.  The  individual  that  is  susceptible 
should,  in  this  view,  be  permitted  to  succumb,  in 
the  interest  of  the  race. 

Of  course,  no  humanitarian  can  give  assent  to 
such  a  literal  application  of  the  knowledge  of  the 
plant  breeder.  Mr.  Burbank  himself  would  be 
the  last  to  suggest  such  an  application.  We  must 
recall  that  the  aggregate  conditions  of  civilization 
are  artificial  in  the  highest  degree;  that  civilized 
man  is  and  must  everywhere  remain  a  hothouse 
plant.  The  essential  province  of  government  is  to 
give  the  weak  protection  against  the  strong,  and 
against  the  adverse  forces  of  nature. 

The  manners  and  customs  of  civilized  society 
have  been  built  up  in  recognition  of  the  fact  that 
persons  weak-bodied  and  susceptible  to  disease 
may  have  attributes  of  mind  that  make  them 
among  the  most  valuable  members  of  society. 

Civilized  man  is  not  reared  to  compete  with 
the  denizens  of  the  jungle,  nor  to  submit  to  the 
hardships  that  may  fall  to  the  lot  of  barbaric 
tribes.  His  case  is  rather  that  of  the  tropical 
plant  transported  to  temperate  zones,  which  may 
require  the  constant  protection  of  a  hothouse 
environment,  being  quite  unable  to  compete  with 
plants  of  the  field,  yet  being  prized  for  the  flow- 
ers that  it  puts  forth,  and  regarded  as  fully  worth 
the  solicitous  care  necessarily  bestowed  upon  it. 

Viewed  in  this  light,  the  work  of  the  euthenist 
[327] 


LUTHER  BURBANK 

who  seeks  to  better  the  environment  of  the  race 
takes  on  a  quite  different  aspect.  The  physical 
weakling  that  is  saved  from  an  early  demise  only 
by  a  pampering  environment  may  prove  an  intel- 
lectual giant — a  Newton,  a  Darwin,  a  Spencer — of 
greater  benefit  to  the  world  than  any  conceivable 
number  of  physical  giants. 

In  a  word,  the  fact  that  man  is  essentially  an 
intellectual  animal  must  be  borne  in  mind  at  all 
stages  of  consideration  of  the  problems  of  the 
eugenist. 

Yet  the  fact  remains  that  the  intellect  of  man 
is  bound  up  with  his  physical  organization;  and 
it  would  be  absurd  to  deny  that  the  problem  of 
the  eugenist  is  primarily  a  physical  one,  even 
though  it  deals  also  with  the  mental  organization. 
The  ideal  man  must  be  sound  of  body  as  well  as 
sound  of  mind;  and  the  ultimate  problem  of  the 
eugenist  is,  how  to  give  us  a  race  of  human  beings 
which  shall  combine  in  the  fullest  measure  phys- 
ical vigor  and  mental  vigor.  ' t  A  sound  mind  in  a 
sound  body,"  was  the  familiar  maxim  of  the 
ancient  Greeks ;  and  it  represents  no  less  fully  the 
ideal  of  the  eugenist  of  to-day. 

If  the  work  of  the  euthenist  preserves  a  cer- 
tain number  of  weaklings  who  might  perhaps,  in 
a  coldly  critical  view,  be  regarded  as  undesirables, 
it  preserves  also  thousands  of  children  who  will 
grow  into  robust  and  vigorous  adults.  We  have 
already  suggested  that  even  those  who  remained 
physical  weaklings  may  have  mental  qualities  that 
far  outbalance  their  physical  defects.  Such  phys- 

[328] 


NURTURE  VERSUS  NATURE 

ical  weaklings  with  wonderful  brains  may  have 
their  strains  blended  with  the  strains  of  other 
individuals  of  robust  physique,  with  the  result  of 
developing  progeny  showing  an  ideal  blending  of 
physical  and  mental  qualities. 

So  in  the  last  analysis  it  appears  that  the  work 
of  the  euthenist  is  in  fullest  harmony  with  that  of 
the  eugenist. 

Or,  better  stated,  euthenics  is  but  an  aspect  of 
the  larger  problems  of  eugenics.  The  ultimate  ob- 
ject at  which  they  both  aim  is  the  development  of 
a  race  of  human  beings  representing  as  close  an 
approximation  as  may  be  to  physical  and  mental 
perfection. 

And  when  we  add  that  such  ideal  personali- 
ties command  the  instinctive  admiration  of  man- 
kind in  general  (witness  the  universally  ap- 
plauded heroes  and  heroines  of  stage  and  story), 
it  requires  no  further  argument  to  show  that  in 
their  ultimate  influence  eugenics,  euthenics,  and 
normal  love  between  the  sexes  are  linked  in  a 
triumvirate  at  once  harmonious  and  beneficent. 


THE  END 


INDEX 


Acres,  World's  Most  Productive, 

178. 

Almonds,  Hybrid,  220. 
Amaryllis,    Bulbs    of    Hybrid, 

193. 
Amateur,   Suggestions   for  the, 

74. 
Animal  World,  The,  301. 

Beans,  Hybridizing,  114. 
Breeding,  Complex  Factors,  158. 
for  Genius,  289. 
from  the  Unfit,  250. 
"         of  the  Unfit,  310. 
"         Selective  Line,  33. 
Budding,  The  Process  of,  67. 
Burbank,  Early  Experiments,  5. 
Methods  and  the  Hu- 
man Plant,  18. 
"         Methods    in    Outline, 

245. 

Potato,  108. 

Burbank's  Migration  to  Califor- 
nia, 6. 


Cactus,  Spineless,  104. 
Calla,  Making  a  Fragrant,  134. 
Characters,    Accentuating    De- 
sired, 165. 
"          Fixing,  38. 
Chestnut,  Dwarf,  208. 

"        Trees,  207. 
Chicken  vs.  Egg,  267. 
Color,    Studies    in    Variation, 

162. 
Corn,  Experiments  with  Sweet, 

117. 
"     Modern,  and  its  Ancestry, 

121. 

Crinum,  Bulbs  of  Hybrid,  193. 
Crops,  Rotation  of,  187. 
Crossing,      Selection     without, 
112. 


Dahlia,  Studies  in  Color,  198. 
"      Working  with   the  Re- 
sponsive, 195. 
Darwin,  24. 

Degeneracy,      Inbreeding      for, 
292. 

Elm  Trees,  235. 

Environment  and  Heredity,  299. 

Eugenics,  Positive,  321. 

The  Principle  of,  304. 
Eugenist,  Nature  as,  307. 
Euthenics,  The  Province  of,  324. 

Flower,  Ornamental  Beds,  182. 
Flowers,  Some  Gigantic,  190. 
The  Colors  Explained, 

36. 

Why  They  Have  Per- 
fume,  133. 
Fruit,  The  Most  Prolific  Bearer, 

103. 
Fruits,  Creating  New,  72. 

"       Culture  of  Garden,   81. 
"       New,    for   Orchard  and 

Garden,  14. 

"       Small,  that  Await  De- 
velopment, 99. 
"       Some  New,  101. 

Galton's  Law,  Aid  from,  254 
Genius,  Breeding  for,  289. 
Germ-cell,    Mechanism    of    the, 

270. 
Germ-Plasm,  Continuity  of  the, 

264. 
"  Modification  of  the, 

265. 
"  Mingling  Modified, 

275. 

Gladiolus,  Improving  the,  184. 
Grafting,    Hurrying    Seedlings 

by,  64. 
Grass,  Substitutes  for,  172. 


[331] 


INDEX 


Heredities,  Remote,  168. 
Heredity  and  Environment,  299. 

Facts  of,  272. 
"  Mendelian,     31,     256, 

281. 

Hints,  Some  Practical,  90. 
Hybrid     Almonds,  220. 

Bulbs   of  Crinum  and 

Amaryllis,  193. 
Peaches,  221. 

"         Strange,  Poppies,   146. 
Trees,  215. 
Walnuts,   217. 
Hybrids,   Quantity  Production, 

85. 

Remarkable,  82. 
Hybridization     and    Variation, 

277. 
Hybridizing    Peas    and    Beans, 

114. 
Possibilities,  223. 

Inbreeding  for  Degeneracy,  292. 
Insanity  and  Mendelism,  287. 

Lawn,  Care  of,  174. 
Leaf,  Changing  a,  138. 
Lilies,  New,   144. 

Marriage,  in  Cousins,  258. 

Marriages,  The  Question  of  Re- 
stricting, 319. 

Mendel,  Experiments,  115. 

Mendelian  Heredity,  31,  256, 
281. 

Mendelism  and  Insanity,  287. 

Monterey  Pine,  295. 

Mutants,  Production  of,  279. 


Nature  as  Eugenist,  307. 
Nature's  Game  of  Chance,  283. 

Old  Methods,  New  Application 

of,  8. 
Orchards    and    Gardens,    New 

Fruits  for,  14. 

Paradox  Walnut,  214. 
Parents,  Selection  of,  246. 
Pea,  Making  to  Order  a,  110. 
Peaches,  Hybrid,  221. 
Peas,  Hybridizing,  114. 


Pecan  Nut,  224. 
Perfume  in  Flowers,  133. 
Pine,  The  Monterey,  295. 
Plant  Breeding,  New  Knowledge 

from,  242. 
Plumcot,  73. 
Plums,  72. 

Pollenizing,  Methods  of,  154. 
Poppies,  Strange  Hybrid,  146. 
Poppy,  New  Colors  in  the,  136. 
Potato,     Combining    with    To- 
mato, 122. 
"       The  Burbank,  108. 

Rhubarb,    The    Giant    Winter, 

297. 
Royal  Walnut,  213. 

Seed,  Planting  the,  50. 
Seedlings,  Care  of  the,  51. 

How  to  Select,  63. 
"         Hurrying    by    Graft- 
ing, 64. 

Seeds  and  Seedlings,  59. 
"       The      Choice    and    Care, 

46. 
Selection      without      Crossing, 

112. 

Shrubs,  Ornamental,  201. 
Soil,  Preparing  the,  48. 
Species,    Constructing    a    New, 

140. 

"        Creating   New,    57. 
"         Quantity      Production, 

143. 
"       The    Origin    of,    148. 


Thornless  Blackberry,  95. 
Tomato,    Combining    with    Po- 
tato, 122. 
Tree,  Chestnut,  207. 

"     Elm,  235. 

Trees,     Development     through 
Selection,  226. 

"       Giants,  212. 

"       Hybrid,  215. 

"      Ornamental,   231. 

"       Second-Generation,  217. 

"       Walnut,   213. 
Unfit,    Restricting    the    Fecun- 
dity, 313. 

"      The  Breeding  of,  310. 

[332] 


INDEX 

Variation    and  'Hybridization,  Vines,  Ornamental,  201. 

277. 

Varieties,  Production  and  Fix-  Walnut,  Paper  Shell,  228. 

ing  New,  151.  "        Paradox,  214. 

Seeking  New,  70.  "         Royal,   213. 

"        to  Order,  87.  "        Trees,  213. 

Vegetables  and  Flowers,  New,  Water,  Supplying,  180. 

16.  White,   Blackberry,  Making  a, 
"         Varied,    126.  93. 


[333] 


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